The opportunity to become a moderator depends on site settings defined by site administrator. To find out if you have this opportunity, open the "Help" tab on the widget:
Scroll down to the "Ranks" section. You will see a free effect available for every rank. In case you find the “This rank gives you moderation rights” description you can become the moderator in this site.
If you do not have enough points use this instruсtion to get more.
Note: A user invited as a moderator by site administrator has more privileges than a user who has become moderator by getting the required number of points.