This is mycode

Public class OrderApprvlUtility
{
   
     @InvocableMethod
    public static void submitForApproval(List<ccrz__E_Order__c> ordids)
    {
       set<id> orderidsset=new set<id>();
        for(ccrz__E_Order__c Ordr:ordids)
        {
            orderidsset.add(Ordr.id);  
        }
     system.debug(' Inside approval--->' +ordids);
      List<ccrz__E_Order__c> orderList=[select id,createdDate,ccrz__OrderStatus__c,ccrz__Account__r.ccrz__E_AccountGroup__c,(select ccrz__Product__r.RLWS_CF_RL_Merch_Division__c from ccrz__E_OrderItems__r ORDER BY CREATEDDATE ASC LIMIT 1) from ccrz__E_Order__c where id =:orderidsset];
     system.debug(' Inside approval-AFTER -->' +orderList);
        Map<Id,String> orderItemsMerchDiv = new Map<Id,String>();
        Set<Id> accountGrpIds= new Set<Id>();
          //[0].ccrz__E_OrderItems__r
       List<String> merchString=new List<String>();
         Map<Id,ccrz__E_Order__c> orderDateMap = new  Map<Id,ccrz__E_Order__c>();
      for(ccrz__E_Order__c cc: orderList)
      {
          system.debug(' cc.ccrz__E_OrderItems__r' +cc.ccrz__E_OrderItems__r +' status '+cc.ccrz__OrderStatus__c);
          if(null!= cc.ccrz__E_OrderItems__r && cc.ccrz__E_OrderItems__r.size()>0){
           orderItemsMerchDiv.put(cc.id, cc.ccrz__E_OrderItems__r[0].ccrz__Product__r.RLWS_CF_RL_Merch_Division__c);
           orderDateMap.put(cc.id,cc);
           accountGrpIds.add(cc.ccrz__Account__r.ccrz__E_AccountGroup__c);
         }           
      }
       // system.debug('#######:' +merchString);
        List<ccrz__E_AccountGroupPriceList__c> Acgplst = [select ccrz__AccountGroup__c,RLWS_CF_Account_Executive__r.id, RLWS_CF_Account_Executive__r.name,RLWS_CF_Merch_Div__c from ccrz__E_AccountGroupPriceList__c where RLWS_CF_Merch_Div__c =:orderItemsMerchDiv.values() and ccrz__AccountGroup__c=:accountGrpIds ];
       // system.debug([select RLWS_CF_Account_Executive__r.name from ccrz__E_AccountGroupPriceList__c where RLWS_CF_Merch_Div__c ='merchString']);
        Map<String,Id> merchDIVAEMaP=  new Map<String,Id>();
       
        System.debug('Merch div:' +Acgplst );
        for(ccrz__E_AccountGroupPriceList__c accGrp : Acgplst){
            merchDIVAEMaP.put(accGrp.RLWS_CF_Merch_Div__c+'!'+accGrp.ccrz__AccountGroup__c, accGrp.RLWS_CF_Account_Executive__r.id);
        }
        System.debug('Account Executive:' +merchDIVAEMaP);
        Map<id,String> orderids=new Map<id,String>();
         Approval.ProcessSubmitRequest req ;
         Approval.ProcessResult result;
        List<Task> taskList = new List<Task>();
        Task taskObj;
        ccrz__E_Order__c ordObj;
        String orderKey;
        for(Id OrderId :orderDateMap.keySet())
        {
            //orderids.put(Ordr.id,Ordr.Name);
             req= new Approval.ProcessSubmitRequest();
            req.setComments('Submiting for Approval');
             req.setObjectId(OrderId);
            ordObj = orderDateMap.get(OrderId);
            orderKey = orderItemsMerchDiv.get(OrderId)+'!'+ordObj.ccrz__Account__r.ccrz__E_AccountGroup__c;
            req.setNextApproverIds(new Id[] {merchDIVAEMaP.get(orderKey)});
            result = Approval.process(req);
        //    ordObj  = new ccrz__E_Order__c(Id=orderId);
          //     orderDateMap.get(orderId).RLWS_CF_Order_Approver__c = merchDIVAEMaP.get(orderItemsMerchDiv.get(orderId));
           taskObj = createTaskForApproval(merchDIVAEMaP.get(orderKey), ordObj.id,ordObj.createdDate);
            taskList.add(taskObj);
        }
        
        if(!taskList.isEmpty()){
            Database.DMLOptions dmlo = new Database.DMLOptions();
            dmlo.EmailHeader.triggerUserEmail = true;
            Database.insert(taskList, dmlo);
        }
    }  
    
    private static Task createTaskForApproval(Id assignId,Id orderId,DateTime orderCreatedDate){
             Integer taskDays = Integer.valueOf(RLWS_Obj_Task_Duration__c.getInstance('Task Duration').RLWS_CF_Task_Due_Date_duration__c);
             Integer reminderHrs = Integer.valueOf(RLWS_Obj_Task_Duration__c.getInstance('Task Duration').RLWS_CF_Task_Reminder_Hours__c);
             Task taskObj = new Task();
             taskObj.OwnerId = assignId;
             taskObj.WhatId = orderId;
             taskObj.IsReminderSet = true;
             taskObj.ReminderDateTime = orderCreatedDate.addHours(reminderHrs); 
             taskObj.Subject = 'Task to Approve Order';
             taskObj.Priority = 'Medium';
             taskObj.Status = 'Not Started';
             taskObj.Type = 'Email'; 
             taskObj.RLWS_CF_From_Order__c = True;
                taskObj.ActivityDate=Date.valueOf(orderCreatedDate.addDays(taskDays));
             taskObj.Description = 'Task for Approve Order';
            // taskObj.RLWS_CF_Task_Type__c ='From Order';
             return taskObj;
        }

}


Note: New to Apex coding 
 Can you please help to cover this in test class
my test class

@isTest
public class RLWS_Cls_OrderApprvlUtility_Test {
 static testMethod void myTest() {
   List<account> accts;
   Account a = new Account(Name='TestAccount');
            accts.add(a);
  //Create an Task  Record
     Task taskObj = new Task();
             taskObj.OwnerId = UserInfo.getUserId();
             taskObj.IsReminderSet = true;
             taskObj.Subject = 'Task to Approve Order';
             taskObj.Priority = 'Medium';
             taskObj.Status = 'Not Started';
             taskObj.Type = 'Email'; 
             taskObj.ActivityDate=Date.today().addDays(7);
             taskObj.Description = 'Task for Approve Order';
        insert taskObj ;
            
    
   List<ccrz__E_Order__c> ordersToCreate=  new List<ccrz__E_Order__c>();
        ccrz__E_Order__c  orderRecord = new ccrz__E_Order__c   ();
            
          /*  orderRecord.ccrz__BuyerLastName__c = 'Test1';  
            orderRecord.ccrz__OrderStatus__c= 'Order Submitted';
            ordersToCreate.add(orderRecord);
            insert ordersToCreate; 
            */
            for(Integer i=6;i<=100;i++)
              {
               orderRecord=new ccrz__E_Order__c(ccrz__BuyerLastName__c='Test1',ccrz__OrderStatus__c='Order Submitted');
               ordersToCreate.add(orderRecord);
              }
              insert ordersToCreate;
            
      test.startTest();
      
  //RLWS_Cls_OrderApprvlUtility Ordersubmit = new RLWS_Cls_OrderApprvlUtility ();
  RLWS_Cls_OrderApprvlUtility.submitForApproval(ordersToCreate);
  test.stopTest();
  }
}