There are no Firefox extensions for Firefox on iOS/iPadOS as you can thank Apple's restrictions on what browser engine can be used. There are only Firefox Extensions for Firefox on Android and on desktop as in Windows, macOS, and Linux.

https://support.mozilla.org/en-US/kb/add-ons-firefox-ios

Other browsers manage to get Adblock working though and they have the same restrictions: Brave is the best example, but Vivaldi also has Adblock and there are more browsers. Arc as one of the newer ones also blocks ads. Brave and Vivaldi even block YouTube and YouTube Music ads. I feel like there is no excuse on why we can’t have ad-blocker capabilities on iOS. It is the only reason why I do not want to use it as main browser as it simply is worse on iOS than Brave or Vivaldi (or Safari). I know there are restrictions and that currently basically all browsers are Safari versions, however it is proven to be possible.