There is no specific time or mentioned time that you need to stay active here, Although if any other member finds your post best or feels it deserves merit he/she will give you merits just focus on sharing quality posts and constructive posts. Besides this do not use any shortcut to get merits because if you get caught by the watcher using any shortcut way to earn merits your account can be tagged as negative feedback. Now, you may think about what kind of shortcuts I am talking about so there are some things you need to follow to build your reputation good on the forum.

Do not use AI-generated based content, Do not copy past from other sources and if you are doing this must share the link of the sources from where you copy/quote the data. Just stay natural and keep active on the forum, and keep participating in the hot discussions where there chances of getting merits are high in this way you may get merits.