All the details for adding a chapter to the map and listing on this forum are documented here:
All the details to start a chapter are documented here:
But the short version of it all is that you need a website or social media page that you manage yourself. With that information I can create a listing with some sane defaults if you don’t want to be bothered by those details.
Creating a map entry here on the forum can help you with exposure, but it’s not the only step. Maintaining a chapter is a grassroots effort. Of course, if you have any questions, you could ask them here, but if those questions are detailed, you could consider creating a topic in Activism > Support