dPlugins Oxy Font Manager
Convert Variable Font OTF to WOFF2
If you are using online font generators they will break variable fonts as they are designed for static font faces. They will remove all except the default font face.
Create a folder on your desktop. Open your terminal.
Type CD and drag your folder. That way you don't need to type your path.
git clone --recursive https://github.com/google/woff2.git cd woff2 make clean all
You will get a converted .woff2 file next to your file.