Expire and Disable HSTS

Thank you all for your advice! Really appreciate it.

I followed the Mailgun instructions to set up https:// and they enabled on their side. Now all their links begin with https: , however I am getting a new error:

Your connection is not private: NET::ERR_CERT_COMMON_NAME_INVALID (Full text below)

I researched a little bit and it looks like this could be an issue with SSL certificate and Cloudflare? The CNAME points to mailgun.org and is DNS only. But maybe this url is not working with Cloudflare?

Any help would be much appreciated! (Step by step would be great - because I’m pretty much a novice at this.)

Many thanks to you all,
Chris

NET::ERR_CERT_COMMON_NAME_INVALID
Subject: mailgun.org

Issuer: R3

Expires on: Dec 21, 2021

Current date: Oct 26, 2021

PEM encoded chain:
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Certificate Transparency:

SCT Cloudflare ‘Nimbus2021’ Log (Embedded in certificate, Verified)

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