The official website of Indico is getindico.io, there you can find useful information related to the project.
We use IRC as our main means of real-time communication with the development community. Get in touch through the official #indico channel on Libera.Chat (irc.libera.chat). It is also accessible through Matrix.
For more elaborate questions and discussions we encourage you to use our discussion forum.
We use GitHub issues for specific bug reports and feature requests. Support enquiries are better suited for the IRC channel or the forums.
Indico has an official Twitter account, @getindico which is occasionally used for announcements.