To apply a top coat or not apply a top coat? That is the question.
When in doubt, apply a top coat. Some of us are really rough on our nails and a top coat can keep nail sets looking good longer. Any top coat works but when I use top coat, I use quick dry top coats because I don't have time to wait for nail polish to dry. The dry in 60 seconds top coats work well. You can even apply a base coat before applying nail strips as an added layer of protection for your nails. That can be quick dry too.
At a salon, they apply a base coat and a top coat. You can totally do that if you would like.
Personally, I don't because waiting for nails to dry takes too long. I have tried doing a top coat over some of the nail sets. I have even done a base coat and a top while looking for what the differences. If you use nail polish remover, a base coat might help to remove the strips faster but it seemed pretty close for removal as far as which one is faster.
I know some people have issues with the ends of their nails so you can do a top coat to seal the ends. But all of this is optional so it's whatever works for you.
https://cnd.com/blog/what-is-top-coat-nail-polish-used-for/#:~:text=Nail%20professionals%20seal%20all%20manicures,things%20your%20hands%20regularly%20touch.
https://youtube.com/@FeelGoodKarma