Obtain the Wurst Client v7.19 MC1.18.1 file from a trusted source (like the official Wurst Client website).
By default, press Right CTRL to open the ClickGUI. Download Wurst v7.19 MC1.18.1
Open your Minecraft Launcher, select the Fabric 1.18.1 profile, and hit Play. Usage & Safety Obtain the Wurst Client v7