Makes the inbox button link directly to activity, marks all gifts as read, keeping the number of notifications in the red dot equal to the number of unread activity (old number - promos = only activity).
1) This script replaces the url of your inbox button with a direct link to your activity notifications, where you can find all the personal likes, comments, etc. Normally it leads to an /inbox/messages page, which is a list of promotional messages.
2) If there is a number of unread messages, script checks for new promos, marks them all read and refreshes the page. As a result, the number of unread items won't include any promos and will be equal to your unread activity (or zero). This works wherever you are on the website, you don't need to go to your inbox to dismiss unread promos. Promos don't disappear, you can still check them in your "Messages" tab.
Script will make additional web requests to Tapas if there's a number of unread notifications, so I recommend marking your activity as read after you've checked it.
There is a nice help page on GreasyFork: How to install user scripts.
Basically, look at the list of browser add-ons on there and install the appropriate one (I recommend whatever is free - Tampermonkey on Windows is what I use, and Userscripts for Safari seem to be a good choice [video on how to use]),
when that's done come back to this page and press the green button at the top ☝. Your add-on will download the script, and then you'll probably need to accept/save it.
after that visit Tapas/reload existing open tabs, and it should work.