can't leave RTX beta

I have minecraft windows edition, and today for no reason i have RTX beta but i dont want it.

i need standard version to play with my friends i need  version 1.14.6 but now i have MC updated to 1.15.8 RTX beta. please help me to get back to 1.14.6

 

im not betatester. i  dont use  Xbox Insider Hub app