dragonxi oooh my misunderstanding! You mean to change the app that is assigned to a site, not changing an application's type.
To change the app on a site:
- Go to https://my.opalstack.com/domains/.
- Locate your site in the site table in the lower half of the page.
- Click the edit icon (in the rightmost column) for that site.
- Change your apps as needed in the site edit form.
- Click the green Update Site button on the edit form to save your changes.
Note that at this time the new UI does not work well on very small screens. If the site table doesn't appear for you at https://my.opalstack.com/domains/ on your device then try rotating the device to landscape mode or use your mobile browser's "request desktop site" feature.