Cannot import certificate on my qnap server

[Wizurth]

Hello,
I can't import the certificate generated by lego on my qnap web server. It didn't install automatically but no error is specified. The docs are useless, they don't mention this problem at all, at least one step is missing.

When I try to import the certificate via the qnap web interface, it displays a "Configuration failed" error.

Could someone please help me?

Wiz.