How do I add an A record to my app on App Platform?

You cannot map A records to apps deployed on App Platform because we do not provide static IP addresses for them. However, you can still add a custom domain to your app using a few different methods.

Add the root domain to the list of domains in the app’s settings along with the wildcard subdomain.
Use Punycode to add a non-ASCII domain name to DigitalOcean.
Our DNS recursive servers now require Authoritative Answer flags when resolving host names.