How to Practicing many 1 move checkmates

I want my grand son to practice many 1 move checkmates. Any suggestions on where to find a random set of hundreds of such checkmates? Thx

Have a look: www.reddit.com/r/chess/comments/9n0ls2/mate_in_one_challenge/

Sarg0n‘s life hack: just post a lot, ev‘rytime a mate in 1 to solve.