Laravel Eloquent Relationship has the same foreign key on the same table

I'm a beginner in Laravel and currently trying to create a ticketing system. My tickets table has two columns which both reference id from the users table namely user_id and handled_by. I am trying to eager load the full_name of handled_by but it is throwing an error "Trying to get property 'full_name' of non-object". I would like to know how to properly create an eloquent relationship between handled_by and tickets so I could display the handled_by's full_name. Below are snippets of my code.

User Model:

 public function tickets(){
        return $this->hasMany('\App\Ticket');
    }

 public function handledBy(){
      return $this->hasMany('\App\User', 'handled_by', 'id');
  } 

Ticket Model:

public function user(){
  return $this->belongsTo('\App\User');
}
public function handledBy(){
  return $this->belongsTo('\App\User', 'handled_by', 'id');
}

View:

@foreach($tickets as $ticket)
<td class="align-middle text-center">{{ $ticket->handled_by->full_name}}</td>
@endforeach

Controller:

$tickets = Ticket::all()->where('status_id', '1');
return view('admin.open_tickets', compact('tickets'));