I request a metadata file to connect ADFS with SAML SSO.
Note: You must complete Step 1. Configure Calendly before sending a message, since Step 1 creates an IdP record in Okta.
Once you receive the metadata file from Calendly, go to Microsoft AD FS, locate Relying Party Trusts, select Import data about the relying party from a file, and upload the metadata file. For more details, view the screenshot below and Microsoft's To create a claims aware Relying Party Trust using federation metadata.
Once you upload the metadata file, go to Calendly, navigate to Account, Organization Settings, then Single sign-on.
Under Step Two: Enable SSO for yourself, selectTest connection.