There is no version 12.4 for Elements. The version you have downloaded is for the full Photoshop and will not work with Elements which is still at version 12 as you have seen.
As a new version of Elements is expected within one month or so, it's possible it will have the 12.4 version but nobody who knows is allowed to say. Anyway don't expect any update for PSE2020.
The usual advice is to download the free Adobe DNGconverter (version 12.4).
https://community.adobe.com/t5/photoshop-elements/faq-will-photoshop-elements-work-with-my-camera-or-why-won-t-my-raw-files-open/td-p/4303022?page=1
That standalone software (not a plugin) can convert a whole folder of your raw files to the DNG format that your PSE2020 can read and edit in the ACR converter. An additional batch operation, but free and with the same quality.