How can I restrict access to streaming on using Workers on the free plan?

Hi guys, I currently have my video content restricted within vimeo.
Vimeo only allows me to send 5GB per month on my plan, and I need to send about 15GB per month.

So I configured a solution using CDN and I’m already streaming it using cloudflare, however the content appears unprotected in the html code.

Currently content is restricted by domain, so a simple solution like that would be great for me.

The token firewall solution offered by cloudflare is too expensive for me.

I would like to know how I can do this using Worker, is it possible?