S3 with Cloudflare R2

It doesnt seem to work for me I setup AWS S3 and got that working fine, and it also showed me the basics, but when I went to using cloudflares R2 which supports S3 it doesnt seem to work, any thoughts?

for more context I followed their guide:

setting <https://<ACCOUNT_ID>.r2.cloudflarestorage.com> as the Backend URL

and setup a S3 API which is the equivelent to a User on AWS for AMP access

put in the keys for access, and set region to auto, as they had stated. I also tried it empty to no avail