@robi I've managed to get this working using Digital Ocean Spaces on my Cloudron Nextcloud installation by following the instructions at this resource. This involved simply editing the config/config.php file to include the following:
'objectstore' => array ( 'class' => '\\OC\\Files\\ObjectStore\\S3', 'arguments' => array ( 'bucket' => 'yourbucketname', 'key' => 'YOURKEY', 'secret' => 'YOURSECRET', 'hostname' => 'nyc3.digitaloceanspaces.com', 'region' => 'nyc3', 'port' => 443, 'use_ssl' => true, 'use_path_style' => true, ), ), );
I added this to the very end of my config.php, and before the last closing );
Functionality tested and working. Uploads and downloads happen directly within the DO Spaces bucket. Configuration persists between reboots.
I am new to Cloudron, so I am not certain if these changes will persist after updates to the Nextcloud app or Cloudron.