Sounds like you're using SSSL on Tiramisu? If so just boot without an SD card and Mii Maker should be accessible like normal.
Note that SSSL doesn't support all features through. For the full Pretendo experience you need Inkay on Aroma. See...
Hello everyone, I'm trying to connect to pretendo, but stuck on creating a new user, it needs to be linked mii but instead it opens homrew launcher, When I press the home button, apparently the application opens as usual, and not for binding...
Click on your profile pic in the top right corner, and you'll get the profile menu popup, with the profile icon highlighted at the top, and the "bookmarks" banner next to it in gray. Click on that icon and you'll get a list of your bookmarks.