I’ve read recently on WebDesignerDepot about Cloudinary, a tool that does exactly what you described.

I’m not sure how you can embed it in your site, but I guess you can:.
See a quote I find on their site:

“Simple and fast integration
Cloudinary’s dynamic URL-based image delivery greatly simplify the integration with your website and mobile app.
Customize your delivery URLs, leveraging your own domain and a flexible SEO-friendly naming convention.”

See a tutorial below.

https://www.webdesignerdepot.com/2017/07/how-to-build-banners-with-custom-fonts-using-just-urls/

Hope it helps!