My Code:

Apex Class:
--------------------

public class LookupApexAuraServices {
@AuraEnabled
    public static List<Lead> ChooseExistingAcc(string leadId, string accountId){
        List<Lead> convertedList = new List<Lead>();
        Database.LeadConvert lc = new Database.LeadConvert();
        lc.setLeadId(leadId);
        lc.setAccountId(accountId);
        lc.setDoNotCreateOpportunity(true);
        LeadStatus convertStatus = [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true LIMIT 1];
        lc.setConvertedStatus(convertStatus.MasterLabel);
        Database.LeadConvertResult lcr = Database.convertLead(lc);
        convertedList = [SELECT Id, Name, RecordTypeId, 
                         IsConverted, ConvertedAccountId, ConvertedContactId 
                         FROM Lead where id =:leadId limit 1];
        system.debug('convertedList : '+convertedList);
        return convertedList;
    }
}

Test Class:
------------------
@IsTest
public class LookupApexAuraServices_Test {
    private class RestMock implements HttpCalloutMock {
        public HTTPResponse respond(HTTPRequest req) {
            String fullJson = 'your Json Response';
            
            HTTPResponse res = new HTTPResponse();
            res.setHeader('Content-Type', 'text/json');
            res.setBody(fullJson);
            res.setStatusCode(200);
            return res;
        }
    }
static testmethod void testChooseExistingAcc(){
        Id devRecordTypeId = Schema.SObjectType.Account.getRecordTypeInfosByName().get('Person Account').getRecordTypeId();
        List<Account> acclist = new List<Account>();
        Account a = new Account();
        a.RecordTypeId = devRecordTypeId;
        a.FirstName = 'Accfname';
        a.LastName = 'AccTestLName';
        acclist.add(a);
        insert acclist;
        List<Lead> leadlst = new List<Lead>();
        lead l = new lead();
        l.FirstName = 'testf';
        l.LastName = 'testlast';
        l.Email = 'asdfg@gmail.com';
        leadlst.add(l);
        lead ld = new lead();
        ld.FirstName = 'testfirst';
        ld.LastName = 'testlast';
        ld.Email = 'asdf@gmail.com';
        leadlst.add(ld);
        insert leadlst;
        Test.startTest();
        Test.setMock(HttpCalloutMock.class, new RestMock());
        LookupApexAuraServices.ChooseExistingAcc(ld.Id, a.Id);
        Test.stopTest();
    }
}
Code COverage is 95% but while deployment getting this error
Getting This Error While Validating in Production during Production "System.DmlException: ConvertLead failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Your lead is missing a field mapping for the fields. For help, talk with your admin" ....?
Please Help Me guys.