Disable YouTube app in settings. Sideload a third-party YT client.
First you have to see if YouTube is a system app on your device. If it is you can't downgrade. If it's not you could check APKPure to see if they have older versions. You may also want to look up SmartTubeNext as an alternative YouTube app.
You don't. It's a system app
Go to settings> device preferences> apps> YouTube & select "uninstall updates"
SmartTubeNext