@asb Unfortunately, this solution is not working for me. I configured a space first (bucketname e.g. bucket1), but NextCloud is trying to PUT a bucket of that name for storage. The bucket name already exists, so the configuration fails. "Creation of bucket 'bucket1' failed. Error executing Create Bucket on https://bucket1.sfo2.digitaloceanspaces.com. 409 Conflict Bucket Already Exists." From what I can tell, the S3 configuration in NextCloud is expecting to be able to create buckets, but when you use a space, the space itself is already a Bucket, so NextCloud is unable to create it. If you put a Space that doesn't exist as the bucket name, it gives a 403 permission denied, because you can't create buckets in spaces through the API, or at least not through how NextCloud is trying to do it.
For Folder Name I've tried "/" and "AmazonS3." Bucket is 'bucket1'. Hostname is sfo2.digitaloceanspaces.com. Port is left empty. Region is sfo2. Enable SSL is selected. Not sure what else to try. If that doesn't work I probably can't use Spaces for this, which I'd like to.