New-OMIS/app/Models/Departments.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Departments extends Model
{
    use HasFactory;

    protected $table = 'tbl_departments';
    protected $primaryKey = 'department_id';

    protected $guarded = [];
}