Does Plesk support content delivery network (CDN)?
Currently, Plesk does not have any integrations with CDN solutions. Vote for such feature on Plesk UserVoice page.
However, different CDN solutions can be configured externally to work with individual domains hosted on Plesk. Please refer to this page for an overview and examples of different CDNs: https://www.plesk.com/blog/various/free-wordpress-cdn/