Laravel api to check record failes

I'm new to laravel and I'm trying to query the database to check if phone number exist.But when i do so and test with postman it failed. Here is a sample code:

public function mobile_availability(Request $request ){
 $number=customer::where('phone_number',$request->phone)->first();
 if($number) {  {

    return response()->json([
        'status' => 'success',
        'message' => 'Mobile Number is available',
        'data'=>$request->phone,
        'is_available'=>'true'
    ]);

}else {

    return response()->json([
        'status' => 'error',
        'message' => 'Mobile Number is missing. Please try again',
        'is_available'=>'false'
    ], 401);
}

}

via Chebli Mohamed