Try to enter about:config in the address bar and set browser.ml.chat.provider to https://bggpt.ai/ .

This question has come up before. See the following threads, which may be helpful: https://support.mozilla.org/en-US/questions/1534967 Adding custom provider to the chatbot https://support.mozilla.org/en-US/questions/1560681 How to add my own chatbot into AI sidebar?

Your question can also be considered as an idea for improving Firefox or feedback for developers, by providing a way to add a custom chatbot to the AI sidebar using the Firefox user interface. Ideas and feedback are collected on the Mozilla Connect website. For example, here's a related idea on Mozilla Connect: https://connect.mozilla.org/t5/ideas/add-grok-3-to-the-sidebar/idi-p/87242

Try to enter about:config in the address bar and set browser.ml.chat.provider to https://bggpt.ai/ .

WARNING from the moderator team: Changing Firefox preferences from the about:config page can sometimes break Firefox or cause strange behavior. You should only do this if you know what you're doing. Please read Firefox advanced customization and configuration options to learn more.

about:config trick worked for me. Thanks a lot.