I don't recomend a Wi-Fi extender because many of them have a 15 year old Wi-Fi version and even if you get a pricey Wi-Fi 6 one you have to keep switching networks and even though it increases range it will be much slower and depending on your budget either add extra routers by using ethernet, get mesh Wi-Fi, and if you have a really really high budget go with Ubiquiti Wi-Fi 6 APs because they are some of the best routers you can get.