trigger updateProjectTeammember on opportunityTeamMember(after insert, after update, after delete){
        if(trigger.isInsert || trigger.isUpdate){
        
        Map<String,String> OppOtmfieldMap=new Map<String,String>();
               OppOtmfieldMap.put('Sr. Client Insights Manager','CEM_Assigned__c');
               OppOtmfieldMap.put('Client Insights Manager','CEM_2nd__c');
               OppOtmfieldMap.put('Data Manager','Ops_Owner__c');
               OppOtmfieldMap.put('Lead Consultant','Consultant_assigned__c');
               OppOtmfieldMap.put('Support Consultant','Consultant_2nd__c');
               OppOtmfieldMap.put('Analysis Support','Analysis_Support__c');
               OppOtmfieldMap.put('BD/Development Partner','BD_Development_Partner__c');
        
        Map<String,String> projOtmfieldMap=new Map<String,String>();
               projOtmfieldMap.put('Sr. Client Insights Manager','Sr_Client_Insights_Manager__c');
               projOtmfieldMap.put('Client Insights Manager','Client_Insights_Manager__c');
               projOtmfieldMap.put('Data Manager','Ops_Manager__c');
               projOtmfieldMap.put('Lead Consultant','Lead_Consultant__c');
               projOtmfieldMap.put('Support Consultant','Support_Consultant__c');
               projOtmfieldMap.put('Analysis Support','Analysis_Support__c');
               projOtmfieldMap.put('BD/Development Partner','BD_Development_Partner__c');
        
            list<id> oppoIdList = new list<id>();
            map<id, id> oppoOtmMap = new map<id, id>();
            list<id> proMemList = new list<id>();
            map<id, id> oppIdProIdMap = new map<id, id>();
            list<id> proId = new list<id>();
            Map<Id,Opportunity> oppIdMap = new Map<Id,Opportunity>();
            Map<id, id> oppIdAccIdMap = new Map<id, id> ();
            Set<id> accId=new Set<Id>();
            
        for(OpportunityTeamMember otm : trigger.new){
                        OppoIdList.add(otm.OpportunityId);
                        oppoOtmMap.put(otm.Id, otm.OpportunityId);
            }
        
        map<id, list<Project__c>> oppIdProjectListMap = new map<id, list<Project__c>>();
        list<Opportunity> oppoList = [select Id, accountId, Project__c, (Select Id, Name from Project__r) From opportunity Where Id In: oppoIdList];
        system.debug('--oppoIdList--' +oppoIdList);
        for(Opportunity op : oppoList){
            proId.add(op.id);
            oppIdMap.put(op.id,op);
            accId.add(op.accountId);
            oppIdAccIdMap.put(op.id, op.accountId);
            oppIdProIdMap.put(op.id, op.Project__c);
            oppIdProjectListMap.put(op.id, op.Project__r);
            }
                
        list<Project_Team__c> ptmListForInsert = new list<Project_Team__c>();
        system.debug('--proId--' +proId);
        system.debug('--accId--' +accId);
        system.debug('--oppIdProIdMap--' +oppIdProIdMap);
        system.debug('--oppIdAccIdMap--' +oppIdAccIdMap); 
        
        list<Project_Team__c> ptmList = [Select id, Account__c, Project__c, Member_Role__c, Team_Member__c From Project_Team__c Where Id In: proId];
        map<id, list<Project_Team__c>> proPtmMap = new map<id, list<Project_Team__c>>();
        system.debug('--ptmList--' +ptmList);
        for(project_Team__c ptm : ptmList){
        
            list<project_Team__c> tempList = proPtmMap.get(ptm.Project__c);
            
            if(templist!= null && templist.Size()>0){
                tempList.add(ptm);
                }else{
                        tempList = new list<project_Team__c>();
                        tempList.add(ptm);
                }
                proPtmMap.put(ptm.Project__c, tempList);
            }
            
        List<project_team__c> projList = new List<project_team__c>();
        for(OpportunityTeamMember otm : trigger.new){
        
            Boolean flag = false;
           
            List<project__c> listOfProj = oppIdProjectListMap.get(otm.OpportunityId);
            
            for(Project__c pro : listOfProj){
                    
            List<project_team__c> listOfPrjTm = proPtmMap.get(pro.id);
            
            if(listOfPrjTm!= null && listOfPrjTm.size()>0){
                for(Project_Team__c ptm : listOfPrjTm){
                    if(otm.userId == ptm.Team_Member__c){
                        flag =true;
                        }
                    }
                }
                if(flag ==true){
                }else{
                    Project_Team__c ptm1 = new Project_Team__c();
                    ptm1.Team_Member__c= otm.userId;
                    ptm1.Member_Role__c = otm.TeamMemberRole;
                    ptm1.Account__c = oppIdAccIdMap.get(otm.OpportunityId);
                    ptm1.Project__c = pro.id;
                    ptmListForInsert.add(ptm1);
                    system.debug('--ptm1--' +ptm1);
                    }
                }
            }
        if(ptmListForInsert.size()>0){

        insert ptmListForInsert;
            }
            
  }
}

i create OppOtmfieldMap want to map this field like whenever Sr. Client Insights Manager add to OTM it save to CEM_Assigned__c which is field of Opportunity how i done next..
Thanx