carloshr

I use ublock origin in Librewolf configured with Blocking mode: medium mode. As this mode blocks all 3rd party scripts and frames by default there's a lot of login sites that don't work because the use of captchas, so after some internet searching I've managed to make it work with following configuration in uBO my rules. You can replace * for a specific domain rule.

recaptcha

* https://www.google.com/recaptcha/ script noop
* https://www.google.com/recaptcha/ sub_frame noop
* https://www.gstatic.com/recaptcha/ script noop
* https://www.recaptcha.net/recaptcha/ script noop
* https://www.recaptcha.net/recaptcha/ sub_frame noop 

hcaptcha

* https://hcaptcha.com/1/api.js script noop
* https://newassets.hcaptcha.com/c/ script noop
* https://newassets.hcaptcha.com/captcha/ script noop
* https://newassets.hcaptcha.com/captcha/ sub_frame noop

I've identified some sites that use other captchas

dropbox

www.dropbox.com dropboxcaptcha.com * noop

aliexpress

login.aliexpress.com https://cf.aliyun.com/nocaptcha/ script noop

If you have other configs you can share here.