"this connection is not private"

That means the web server is using http and not https, or the website is using a faulty or expired certificate, which risks login credentials and other details.

You can usually bypass this by showing the details, and selecting visit anyway.

If this is your website, add or update a certificate and get https support working.

For more info, post a screenshot of the Safari error, with the website details expunged.

sherman140 wrote:

I tried MrHoffman's suggestion. The Reply was "502 Bad Gateway"

That’s usually either a problem with the web server and its related bits, or maybe with an ad-blocker installed locally, or maybe with a locally-installed VPN app or other add-on security apps.

If there are ad-blockers installed disable them, and for any add-on VPNs or add-on security, remove all, and test again.

Temporarily disable iCloud Private Relay, too.

But it’s usually the web server.