There's an update to include more Samsung Galaxy models.
The S20 Ultra, Note 20 Ultra and Z Fold 2 are now able to use the excellent Expert RAW camera app.
Other Galaxy models for 2020. The S20+, S20, Note 20 and the original Flip phones are not compatible with Expert RAW as they don't meet the requirements needed for the app.
It looks like from what I've read, the new supported phone will only be able to use Expert RAW on the primary camera and 12MP Ultra wide lenses.
Make sure you have the latest software and security patch for your device.
Then go into the Galaxy Store and download the app