On the old[0] MyNoise app, there's "Calm Office" which has generators for "Keyboards & Mouse"[1] and "Keyboards"[2].

There's also "Vintage Office" which has "Mechanical Keyboard"[3].

Both have a variety of other ambiences that could fill out "typing room" (especially if you made a multi-generator.)

But yeah, it could do with a bit more variety of "office" and "keyboard" generators.

[0] I dislike the new app's UI/UX, it doesn't support multi-generators, and there's no easy way to download all the generators you have access to. (You also have to pay again for lifetime access but that I'm fine with.)

[1] "thock"

[2] "clatter"

[3] kind of a watery thock?

Tons of ten-hour-long typing sound videos on YouTube.