Share a case using trigger

Note:
Default access lavel
trigger trgsharingTest on Case (after insert, after update) {
    if(trigger.isAfter==true && (trigger.isInsert==true||trigger.isUpdate==true) && trigger.new.size()>0 && trigger.new!=null)
    {
      List<CaseShare> lstShare=new List<CaseShare>();
        
        for(Case obj:trigger.new )
        {
           CaseShare objShare=new CaseShare();
              objShare.CaseAccessLevel='Edit';
              objShare.CaseId=obj.id;
              objShare.UserOrGroupId='005i00000038RVcAAM';
              lstShare.add(objShare);
        }
        //Database.SaveResult[] jobShareInsertResult = Database.insert(lstShare,false);
        
        insert lstShare;
    }
}