моя проблема решена путем вставки строки, затем извлечения последней записи и вставки в переменную.
DB::table('travelers')->insert([
'faName' => $this->first_name[$i],
'faFamily' => $this->last_name[$i],
'fatherName' => $this->father_name[$i],
'nationalCode' => $this->national_code[$i],
'phone' => $this->phone_number[$i],
'enName' => $this->e_first_name[$i],
'enFamily' => $this->e_last_name[$i],
'email' => $this->email[$i],
'passportNumber' => $this->passport_number[$i],
'expDate' => CustomDateTime::toGreg($this->passport_expire_date[$i]),
'birthDay' => CustomDateTime::toGreg($this->birthday[$i]),
'foreigner' => $foreignerField
]);$ traveller = DB :: table ('travelers') -> orderBy ('id', 'desc') -> first ();