View file ProForum/Files/application/app/Models/SupportMessage.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class SupportMessage extends Model
{
    public function ticket(){
        return $this->belongsTo(SupportTicket::class, 'support_ticket_id', 'id');
    }

    public function admin(){
        return $this->belongsTo(Admin::class, 'admin_id', 'id');
    }

    public function attachments()
    {
        return $this->hasMany(SupportAttachment::class,'support_message_id','id');
    }
}