Error with Indexing

Hi,
I’m not sure if you are able to help me with this or not. If not, just let me know!
I’m having difficulty getting Google to index my site. I keep getting a 403 message that I’ve failed to verify the URL ownership. In my Google Search Console, I have a property for threeheads.works and for threeheadsworks.wpcomstaging. I initially thought I would verify threeheads.works. When I still got the error message, I tried threeheadsworks.wpcomstaging. Got the error message there, too. What am I doing wrong?

Thanks,
Kate