Because Savvii uses NGINX as a web server, your .htaccess file does not work. This file only works if Apache is used as a web server.
For this reason, you cannot add the configuration that you normally put in a .htaccess file yourself. We would like to receive the redirects (or other things) you want to add in a ticket. If you want to add redirects, we'd like to receive them from you in a .csv or .xlsx, with the origin in the first column and the target in the second. We'll check the configuration right in front of you, and we'll do it a.s.a.p.