After activating https i get error "untrusted domain"

[michaelof]

yes, you have to add your domain to the “trusted_domains”, in config.php

E.g.:

‘trusted_domains’ =>
array (
0 => ‘example.com’,
1 => ‘www.example.com’,
),

HowTo: Add a new trusted domain

Trusted domains are used by Nextcloud to prevent Host Header Poisoning. You need to specify every domain at which your Nextcloud can be accessed. This means if you have Nextcloud installed at “192.168.0.29” and also want it to be accessible at “cloud.example.com” you’d need to modify the trusted_domains entry in your config/config.php. The initial config would look like the following: 'trusted_domains' => array ( 0 => '192.168.0.29', ), To add a new domain just add new entries by ap…

https://docs.nextcloud.com/server/18/admin_manual/configuration_server/config_sample_php_parameters.html?highlight=trusted_domains