If you have an Unreal Engine license, head over to quixel.com/pricing, scroll down and click the “Begin for Free” button on the Unreal Engine section:
You will also see a prompt when you sign in to the Megascans library with your Epic Games account.
Once you choose to switch to this plan, you’ll get unlimited points to access the entire library, on Megascans, Bridge, and Mixer.
If you do not have an Unreal Engine license, please review this FAQ: https://help.quixel.com/hc/en-us/articles/360019828837-Why-am-I-getting-Unreal-Engine-License-not-found-when-trying-to-subscribe-to-Unreal-Unlimited-
Please note that any accumulated points will be lost and cannot be used on the same account. If you wish to keep your existing points to use in other Engines/DCCs, we recommend creating a new account for Unreal Unlimited.