Open the Minecraft Launcher and select the "Fabric Loader 1.16.5" profile. How to Use
To install Wurst v7.13, follow these steps as outlined on the official Wurst website :
Download Wurst v7.13 for Minecraft 1.16.5 introduces several utility enhancements and bug fixes to the popular Minecraft hacked client. This version is fully compatible with Minecraft 1.16.5 and requires the Fabric loader to run. New Features & Changes in v7.13
You can now open and use graphical user interfaces (GUIs) while standing inside portals.