UPDATE: I’ve followed the instructions posted here How to modify and load the portal directly from your theme , but after editing config.production.json, the portal doesn’t load. I tried even using the original portal file from https://unpkg.com/@tryghost/portal@~1.12.0/umd/portal.min.js and uploading it into my theme, to make sure it wasn’t a mistake I’d introduced into the file, and it’s the same. So I guess, now, notwithstanding any changes/translations I may add to the portal.min.js file, my question is how to get the portal to load from editing config.production.json.
Otherwise, if there is a way to edit defaults.json directly to point to the new url, that would be great, but I guess the read-only filesystem (of Cloudron install) would prevent that?