How to prevent redirection when validating with a traditional HTTP request?

Hello,

I am using server-fetched partials to fetch some data. Before the fetching, I am using basic validation inside the controller: https://laravel.com/docs/10.x/validation#quick-writing-the-validation-logic

public function getServerFetchedPartial(Request $request)
{
    $validated = $request->validate([
        'input1' => 'required|unique:posts|max:255',
        'input2' => 'required',
    ]);

    // return the data
}

Now if it passes, everything works fine and I get the data to the place I want in the blade file. However when validation fails, it returns the entire failed message to the designated area in the blade file, as seen in the docs:

If validation fails during a traditional HTTP request, a redirect response to the previous URL will be generated

In my case it's a modal, and it simply puts the entire error page inside a little modal.

How can I somehow "catch" this redirection and send custom error?