how to setup custom domain

I'm trying to setup a domain for sendgrid email verification. When I add the domain I get an error that
Unreachable cname target (localhost). Please check app domain target

Is this Cloud or Self-hosted?

Self hosted

And you want to send emails via Sendgrid from your Appwrite Console domain?

Yes

I have purchased the domain and I want to link it

Does going to the domain currently shows your Appwrite Console?

Yes. I have already redirected the ip to the domain

And you're trying to follow this?

Would you be OK with sharing your domain so that I can see it's DNS records?