Hi  @UnknownMonster 

Currently, only Omada Switch in standalone mode can allow you to import your HTTPS certificate.

Another solution is to use Omada Controller to manage your router/EAP. The Controller can import the HTTPS certificate; And once the router/EAP are managed by the controller, their standalone web interface will not be useful. (you can set up Access Control to deny any access to the standalone web interface via the controller)