There ARE apps for this. The key really is getting yourself comfortable with home keys. You don't have to have perfect form but you DO have to learn how to type with more than just two fingers.

is Typing Of The Dead still around?

I practice pretty regularly with monkeytype.com. I don’t know that it’s designed to specifically help learn touch typing, but it’s decent. There is also keybr.com which is designed to help you focus on specific letters that you struggle with.

My ZSA keyboards also have whack-a-mole style training but I think it relies on the web-serial connection to support that, and it shows the location on my board when I miss something.

Felling like a real clown trying to search for a TYPING LESSON for PYTHON code.

I made myself not look whilst writing stuff for work, but what really helped was being continually cognisant where my fingers were and where/how to move between keys. it was annoyingly similar to learning a muscle memory sport like swimming or skiing

I did manage to learn how to play guitar and keep 40 chords in my head all this time. I like my chances.

Mavis Beacon or Mrs Anderson slapping you upside the head if you looked at the keys

In total seriousness, The Typing of the Dead is a really good practice option, because it puts time pressure on and has difficulty scaling.