You mentioned the APFS does not appear on the Erase button options. So lets do it, but kind of manually and easily:
Technical info about APFS formatting: Technically, the internal MacOS procedure to format a drive with APFS is first format it using the 'MacOS Journaled Filesystem', than it creates an APFS container, then it switchs the formatted type of the drive from Journaled to APFS, then it inserts the APFS container on the drive, and finally it create volumes inside the container. I am just writing because it may help other who read this. This requires a very recent new version of SuperDuper. Because you mentioned 'latest OS' which mens Catalina. About SuperDuper: Make sure you a running the lastest version of SuperDuper.
