To add a new site, enter an unique title/domain (without www.).
Select options for useragent (like Googlebot), set referer (ignored when Googlebot is set), set random ip-address, block Javascript, block regular expression, unhide text on (or when paywall(selector) redirect to) amp-page and/or load text from json or Google webcache (paywall|article selector).
Custom sites (new) are enabled automatically in Options (cookies will be removed by default unless you enable allow_cookies).
If you want to use custom sites (for non-listed sites) enable it in Opt-in Custom sites enabled:
You can also just request permissions for the custom sites you added yourself & post-release added sites (below).
On Android: to enable custom sites you need the 'custom' add-on version (with access to all sites): Bypass Paywalls Clean (custom)

List of custom sites

* already in default list (double domain)

Json file

You can edit/sort the text area and save (only when json-text is valid). Clear & save to reset. You can also export/import json-text for new installations.