When I start getting rusty, I fire up gtypist. It does key movement exercises (e.g. dedede dwdwdw dsdsds dadada) for many combinations of keys. It really helps. You do need to make sure you're following good typing practices however.
My dear internet strangers, have you been initiated into the wonder that is Typing Of The Dead?
Have 2 minute sessions (2/4/6 minutes total) as a warmup routine with 10k English words to get my fingers moving in the morning.
If anyone is interested - I have written https://typealong.app/ because I wanted to combine reading with typing practice.
keybr.com is my new favorite.
Its one of my top software role models. Minimal UI thats easy on the eyes and loads instantly, adaptive behavior thats ubobstrusive, really useful reports.