Can someone help me with Domain Mapping?

I need some help on mapping my domain. I went through each step giving online but I am now getting two different errors.

The first error is from my url that I am trying to map to. It's giving me a 403 error after we changed the DNS A record.

The other error I get is when I try to map my domain it says, "Domain name is unable to access."

Can anyone help with where we might have went wrong?

Thanks