app-api/app/Models/ApplyUser.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class ApplyUser extends Model{

    protected $table='apply_user';

    public function GetUser(){
        return $this->belongsTo(User::class,'user_id');
    }

    public function GetApplyUser(){
        return $this->belongsTo(User::class,'apply_user_id');
    }
}