#tchncs now hosts a #ntfy push service. If you were already trying ntfy.sh with eg. Mastodon or Matrix but it didn't work, that's because the .sh instance blocks ip's after a certain amount of requests per minute. With https://push.tchncs.de, you can give it another shot.

Configurations such as quota/our own ratelimit are not final yet (but i try my best to make it fair)