Update a table array for loop in laravel

I have a table and I want to update it, but theres always a problem everytime i update, it says its null or request column not found 0, someone can help me? Any idea?

Update controller

 public function update(Request $request, string $id)
    {
        

          $invoice = Invoice::find($id);
          $input = $request->all();
          $invoice->update($input);

        $title = $request->title;
        $quantity = $request->quantity;
        $unit_price = $request->unit_price;
        $sort_order = $request->sort_order;

            $invoiceDetails = [];

            for ($i = 0; $i < count($title); $i++) {
                $invoiceDetails[] = [
                    'sort_order' => $sort_order[$i],
                    'title' => $title[$i],
                    'quantity' => $quantity[$i],
                    'unit_price' => $unit_price[$i],
                ];
            }

             

            $invoice = $invoice->invoice_detail()->update($invoiceDetails);

        return redirect('invoice')->with('flash_message', 'Updated');

    }

Invoice model

class Invoice extends Model
{
    use HasFactory;
    protected $table = 'invoices';
    protected $primaryKey = 'id';
    protected $fillable = ['user', 'company', 'invoice_month'];
    
    const UPDATED_AT = 'modified';
    const CREATED_AT = 'created';
    
    public function invoice_detail(){
        return $this->hasMany(Invoice_detail::class, 'invoice_id');

    }

}

Invoice detail model

class Invoice_detail extends Model
{
    use HasFactory;
    protected $table = 'invoice_details';
    protected $primaryKey = 'id';
    protected $fillable = ['title', 'quantity', 'unit_price', 'invoice_id'];

    const UPDATED_AT = 'modified';
    const CREATED_AT = 'created';
    public function invoice(){
        return $this->belongsTo(Invoice::class);
    }

}

route

Route::get('invoice', [InvoiceController::class, 'index']);

Route::get('search', [InvoiceController::class, 'search']);

Route::resource('/invoic', InvoiceController::class);

I just want the right code to update in laravel, its in an array, cause my view is a bootstrap table

Updating the child records should not be done like this, update your code to this code because you haven't any primary key ID of the child records. so first delete the child records and recreate them with updated records.

public function update(Request $request, string $id)
{
    $invoice = Invoice::findOrFail($id);
    $invoice->update($request->all());

    $title = $request->title;
    $quantity = $request->quantity;
    $unit_price = $request->unit_price;
    $sort_order = $request->sort_order;

    $invoiceDetails = [];

    for ($i = 0; $i < count($title); $i++) {
        $invoiceDetails[] = [
            'sort_order' => $sort_order[$i],
            'title' => $title[$i],
            'quantity' => $quantity[$i],
            'unit_price' => $unit_price[$i],
        ];
    }
    $invoice->invoice_detail()->delete();
    $invoice->invoice_detail()->createMany($invoiceDetails);

    return redirect('invoice')->with('flash_message', 'Updated');
}