You could also do this for all requests with middleware:

class WithUserId
{
    public function handle(Request $request, Closure $next): Response
    {
        $request->merge([
            'user_id' => $request->input('user_id') ?: $request->user()?->id,
        ]);

        return $next($request);
    }
}

This wouldn't override the user id if it was actually set in the request, but would inject `user_id` into the input for each request that passes through it.