dPlugins Oxy Font Manager
GDRP Friendly fonts in Oxygen Builder
Oxygen is not self-hosting fonts. Builder only provides links to Google's CDN.
Not self-hosting and using Google Fonts CDN will lead to users' ID addresses being personal information leaked. If you are doing that you can pay a big fine. Otherwise, you need to bloat websites with GDPR complainant banners that will ruin design and users' experience.
Oxygen and many other builders by default use Google Fonts CDN.