I can't find any good explanation of how to use interrupts in Sketch.
Have you looked at this page?
Specifically, the sections on attachInterrupt, detachInterrupt, interrupts, and noInterrupts.
These are useful for external interrupts. The search field and button at the top of each page also finds lots of useful information on interrupts.
I have searched the forum, and I can't find any good explanation of how to use interrupts in Sketch.
I didn't have any problem finding stuff.