Yes, its possible to set connection name if your model extends to
Illuminate\Database\Eloquent\Model;
$profile = UserDefaultProfile::setConnection('your_connection_name_goes_here')->where('','')->select('');
$input['user_id'] = $request->user_id;
$input['page']=$request->page;
$lang=$request->lang; //$lang Variable for connection name for a particular database
$input['ip']= request()->ip();//request()->getClientIp();
$user = CalActivity::on($lang)->create($input);
$success['a']="";
return $this->sendResponse($success, 'activity record successfully.');