You have a Page Rule for www to redirect to yourdomain.com, but may I ask have you got an A www record at DNS tab of Cloudflare dashboard for your domain?
From the screenshot above, you have only CNAME popswap.org, but I do not see any www here.
Kindly, add a new CNAME www (name column) and point it to @ (content column).
Moreover, from the screenshot above, it’s only DNS mode and I am concerned that Page Rules or any other settings at Cloudflare do not have an influence on your domain (not being - proxied via Cloudflare?).
Regarding the Page Rule, it should be the: www.popswap.org/* with “Forwarding URL - 301 Permanent Redirect” option and the value of https://popswap.org/$1 (meaning redirect each request from www to non-www domain)