prepareForValidation Doesn't work anymore

the database columns are email, phone and the input names are admission_email, admission_phone whenever i submit the form they show as null in the database for some reason. I used to use this method to do this type of thing but it doesn't work anymore am i missing something??

<?php

namespace App\Http\Requests\Pages;
use Illuminate\Support\Facades\Auth;


use Illuminate\Foundation\Http\FormRequest;

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

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array|string>
     */
    public function rules(): array
    {
        return [
            'admission_email' => 'required|email|unique:admissions,email',
            'admission_phone' => 'required|numeric|digits_between:10,14',
            'address' => 'required|string|max:255',
            'student.*.student_name' => 'required|string|max:255',
            'student.*.admission_category_id' => 'required|numeric|exists:admission_categories,id',
            'student.*.class_room_id' => 'required|numeric|exists:class_rooms,id',
            'student.*.gender' => 'required|string|max:255|in:male,female',
            'student.*.old_grade' => 'required|numeric|min:0|max:100',
        ];
    }

    public function prepareForValidation(): void
    {
        $this->merge([
            'email' => $this->admission_email,
            'phone' => $this->admission_phone,
        ]);
    }

}