Hi @S9Plus welcome to the /e/ forum.
This sounds very much like the “old” Samsung Android recovery. Does the text mention this?
I wrote an article here:
(The link should drop you into the middle of the article.) You should read the section “Your first boot into TWRP”, I think.
Easy Installer is not quite sufficiently explicit on this being slightly hard for anyone who has not flashed a Samsung with a custom ROM.