For business accont I can purge by Cache-Tag but can't save cache with Cache-Tag?

Am I understanding it correctly?
Tried adding cacheTag to fetch cf: {} and also tried setting in response header ( https://httpbin.io/response-headers?Cache-Tag=offers&time=time ) and seems like it's not working

For business accont I can purge by Cache-Tag but can't save cache with Cache-Tag? - Cloudflare Developers