You don't have permission to access "http://www.lowes.com/" on this server.

Onlondore Said:

"You don't have permission to access "http://www.lowes.com/" on this server."

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https://www.lowes.com works for me. Its protocol has HHTPS, using SSL (for encryption).

Try Clearing your Temporary Internet Files (Cookies & Cache) of Safari: Cookies perform remembrance of certain site-entered data. Whereas Cache keeps a snapshot of the last time you visited a site.  Use this Link: Clearing History and Cache - Apple Communities

The link to Lowes works fine for me.

normally those forbidden messages come from the website itself, and there's not much you can do on your side.

However, what browser are you using to access it?

Are you sure you are following a valid link? Are you accessing Lowes from a bookmark? Or by entering the address directly in the browser?

The version of Safari that you are using on High Sierra is still using the old TLS 1.0/1.1 spec security, and Lowes may have updated their site to reject these old, insecure TLS protocols. Try the secure HTTPS on your link attempt and see if you can access the site.

I am using Safari 14.1.1 and I can access Lowes website without issue.

Along the lines of what VikingOSX said, try using a different browser and see if there are still issues. Safari isn't updated on older macOS versions so if you want something up to date you have to go with third party.

As far as I can tell there hasn't been a security update for High Sierra (which you claim to be using) since last year.

Might try this, it's Chrome without google & without Ads...

https://brave.com/