CreateCompanyDiagnosticRequest.php

 <?php

class CreateCompanyDiagnosticRequest 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()
    {
        $rules = ['needs' => 'required|array'];

        $comments = array_filter($this->request->all(), fn($elt) => preg_match('#^comment-[0-9]+$#', $elt),  ARRAY_FILTER_USE_KEY);

        foreach ($comments as $key => $value)
        {
            $rules[$key] = 'nullable|string';
        }

        return $rules;
    }
}

DiagnosticController.php

<?php

class DiagnosticsController extends Controller
{
    /**
     * Store a newly created resource in storage.
     *
     * @param CreateCompanyDiagnosticRequest $request
     * @return RedirectResponse|Redirector
     */
    public function store(CreateCompanyDiagnosticRequest $request)
    {
        $validated = $request->validated();
        $needs_validated = $validated['needs'];
        $comments_validated = array_filter($validated, fn($key) => (preg_match('#^comment-[0-9]+$#', $key) && $validated[$key]), ARRAY_FILTER_USE_KEY);

        if (auth()->guest()) {
            $request->session()->put('pending_company_diagnostic', [
                'user_id' => null,
                'needs' => $needs_validated,
                'comments' => $comments_validated
            ]);

            return redirect(route('login'));
        } else {
            $diagnostic = Diagnostic::create([
                'user_id' => auth()->user()->id,
                'uuid' => uniqid()
            ]);

            $diagnostic->addNeeds($needs_validated);
            foreach ($comments_validated as $key => $content) {
                preg_match('#([0-9]+)$#', $key, $matches);
                $categroryId = $matches[0];
                $comment = new Comment;
                $comment->content = $content;
                $comment->diagnostic()->associate($diagnostic);
                $comment->category()->associate($categroryId);
                $comment->save();
            }

            return redirect($diagnostic->path());
        }
    }
}