Not sure about Epic... but on Steam you just right click on the game in your library and go to properties...
You can then set your version under the Betas option. And set your update policy under Updates
Under Betas, the current stable version is 1.6.2 and the current beta is 1.6.3. Not all mods are maintained or up to date tho... check with the mod. You might actually have to downgrade to an older version - but under the Betas menu, you can pretty much choose any version of the game.