RTX is not being enabled

Correct version of the RTX beta is not getting installed on my computer.  Currently the beta version installed is 1.16, but I don't know how to drop it down to 1.15.  Uninstall and reinstall?  Anyway, any assistance would be great.  One thing to note... I installed this version of minecraft a LONG time ago.  I did not get the 29.99 version.  There was a free version, but it always says that I own the game and that it's installed.  Is that the issue?