Just a small, client-side Bingo generator (used for "Tetris 99 Bingo")
Put it on a webserver. Done. It's all clientside.
Generated boards can be shared with the generated String in the "Share Me:" Box and a string generated by this can be imported into the "Import Fields:" Box.
Add Users for randomized boards, then draw numbers and enter them into the field and click "Check!".
Tested using Chrome, but ought to work with any recent browser.