Help with domain verification

I am having some issues with domain verification for my Zoom OAuth app.
I’ve followed the instructions and uploaded the html file as described and can confirm that it is publicly available but after pressing the Validate button I receive an error message:

can not access the html file, please be sure the file uploaded correctly and retry

Did I misunderstood the instructions?
And is there any other way of verifying domain ownership, like adding TXT records?

Hello @easymeets Please check your DM for more information on this process.

Regards, Kwaku