The approach of using a <template> tag to define OG images inline (so they inherit your page's own CSS, fonts, and Vite assets) is inspired by OG Kit by Peter Suhm.
If you'd rather not self-host the screenshot infrastructure (Chrome, Browsershot, or Cloudflare Browser Rendering), OG Kit is a great hosted alternative. It uses the same inline-template approach, but handles the screenshot generation for you as a service.