Can any one share best option to rpair Outlook OST Error.

1. Custom Approval Page:

• Create Visualforce page that will show current login users’ Approval request
• He should able to accept and reject those from same page with description.
• There should be provision to multi-accept or mulit-reject.
• List view should be there to show update coming and past requests.                                                                                         Any Solution for this. Thanks in advance

Hi, All
I am new to salesforce, can anyone help me to get 100% coverage please 


public class MyContactListController 
{
    @AuraEnabled
    public static List<Contact> getContacts(Id recordId) 
    {
        List<Contact> conList = new List<Contact>();
        try{
            System.debug('--'+recordId);
            conList = [Select Id, FirstName, LastName, Email, Phone From Contact Where AccountId = :recordId];
            System.debug('conlist result----> '+conList);
        }
        catch(Exception e){
            System.debug('inside catch Block  -> '+e.getMessage());
        }
        return conList;
    }
}



-----------------------------------------
TestClass
-----------------------------------------
@isTest
public class MyContactListControllerTest {
   
    static testMethod void getContactsTest(){
        Account ac = new Account(Name='Name1');
        Insert ac;
        List<Account> acList = [select id, name from Account where id!=NULL];
        System.assertEquals(true,acList.size()>0);
        MyContactListController.getContacts(acList[0].id);
        List<Case> case_Obj  =  [SELECT Id,CaseNumber,AccountId From Case WHERE AccountId=:acList[0].Id LIMIT 10];
       
        MyContactListController.getContacts(acList[0].Id); 
      
    }
}

I have signed up for a developer salesforce account and created a Connected App for testing to get the OAuth working and test the API. All seems to be good. My question is now, how do I allow other salesforce instance to use this application? Do I need to package and list it somewhere or how does it work?

Can any one share best option to rpair Outlook OST Error.