@MohamedTammam hello dear tammam, thank you for your respons. im glad you're respond my thread. before i explain my problem, this is my codes

Form Request :

<?php

namespace App\Http\Requests\Product;

use Illuminate\Foundation\Http\FormRequest;

class UpdateProductRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'product_name_en' => 'required',
            'product_name_id' => 'required',
            'product_code' => 'required',
            'product_quantity' => 'required|numeric',
            'product_price' => 'required|numeric',
            'product_discount_name' => 'nullable',
            'product_discount_type' =>  'required_with:product_discount_name|nullable',
            'demo1' => 'required_with:product_discount_name|nullable',
            'product_discount_time' => 'required_with:product_discount_name|nullable',
            'product_discount_start_date' => 'required_with:product_discount_name|nullable|date',
            'product_discount_end_date' => 'required_with:product_discount_name|nullable|date',
            'product_tags_en' => 'required',
            'product_tags_id' => 'required',
            'product_size_en' => 'nullable',
            'product_size_id' => 'nullable',
            'product_color_en' => 'nullable',
            'product_color_id' => 'nullable',
            'product_short_description_en' => 'required',
            'product_short_description_id' => 'required',
            'product_long_description_en' => 'required',
            'product_long_description_id' => 'required',
            'hot_deal' => 'nullable',
            'featured' => 'nullable',
            'special_offer' => 'nullable',
            'special_deal' => 'nullable',
            'category_id' => 'required',
            'subcategory_id' => 'required',
            'subsub_category_id' => 'required',
            'brand_id' => 'required',
        ];
    }

    public function messages() 
    {
        return [
            // Required Discount Without Besides Discount Product Name
            'product_discount_name.required_without' => 'Product discount type, percentage, time, start date and end date fields are required when product discount name is filled.',

            // Required Discount With Discount Product Name
            'product_discount_type.required_with' => 'Product discount type field is required when product discount name is filled.',
            'demo1.required_with' => 'Product discount percentage field is required when product discount name is filled.',
            'product_discount_time.required_with' => 'Product discount time field is required when product discount name is filled.',
            'product_discount_start_date.required_with' => 'Product discount start date field is required when product discount name is filled.',
            'product_discount_end_date.required_with' => 'Product discount end date field is required when product discount name is filled.',

        ];
    }

}

Method Update

public function manageUpdateProduct(UpdateProductRequest $request, $id)
    {
        $validated = $request->validated();
        
        $validated['product_slug_en'] = Str::slug($validated['product_name_en']);
        $validated['product_slug_id'] = Str::slug($validated['product_name_id']);

        Product::where('id', $id)->update($validated);

        $notification = array(
            'message' => 'Product Updated Successfully',
            'alert-type' => 'success'
        );

        return redirect()->route('manage.product')->with($notification);
    }

So in my case, i want to insert data table to field "product_discount_percentage" with Form Request but there's a problem which is the name's of input request for "product_discount_percentage" is a "demo1". i can't change it that name, because i need it for running the scripts from library. So i must using name "demo1" for insert data to table field "product_discount_percentage". So how can i fix this, without change the name of input request. So it's like i want to overriding the input request "demo1" to be "product_discount_percentage". Can I do that?...

Thank You @mohamedtammam , I hope you understand about what im saying. and sorry if My English's Bad.

@adnanerlansyah403

You can add the prepareForValidation() method on your FormRequest, something like this:

protected function prepareForValidation()
{
    $this->merge([
        'product_discount_percetange' => $this->demo_1,
    ]);
}

Then on your validation add the product_discount_percentage rule, and you should be good to go.

@undeportedmexican oh yea that works!!! Thank you so much my friends.

@adnanerlansyah403 Glad it's solved, please mark the discussion as solved.