Hi, it seems there is an issue that prevents you from turning off the banner even if you bought a domain from Hostinger.
I have contacted a developer about the issue (c.c. @mantas.daraciunas) and I’m waiting for a reply. I also asked for a feature to manually override the branding switch for future cases like this, when domain verification fails.
When I have a reply, the branding will be removed. Sorry for the inconvenience, and thanks for your patience.