Sites that block copy and/or paste drive me nuts. Most especially are the ones where they want you to type in your password or email address multiple times. Look man, I use a password manager for a really good reason and I don't need your 2 bit website to try and convince me otherwise.

Luckily in Firefox there's a way to disable that nonsense. Just set dom.event.clipboardevents.enabled=false and problem solved.

h/t https://digiwonk.gadgethacks.com/how-to/re-enable-copy-paste-annoying-sites-block-0155910/