There is no way to access API from user script anymore. You can manually open character sheet https://www.dndbeyond.com/characters/IDCHARACTER, open dev tools (F12), open Network tab, filter queries by IDCHARACTER and find IDCHARACTER?includeCustomItems=true. There is one OPTIONS and one GET. GET has response - you can copy response via context menu. But I find this json useless for my purpose.
There is no way to access API from user script anymore. You can manually open character sheet https://www.dndbeyond.com/characters/IDCHARACTER, open dev tools (F12), open Network tab, filter queries by IDCHARACTER and find IDCHARACTER?includeCustomItems=true. There is one OPTIONS and one GET. GET has response - you can copy response via context menu. But I find this json useless for my purpose.