The error message was like
Please use the command line updater, the browser update is disabled in config.php.
For further help, please refer to the documentation.
To use the command line updater
SSH into your umbrel server
ssh umbrel@your_ip_adress
then
sudo docker exec -it nextcloud_web_1 bash
su -s /bin/bash www-data -c “php occ upgrade”
This should help