Hey Alberto
It's not fully supported today as the browser will complain about TLS as the certificate won't be for the same domain.
You can define a CNAME.
If your cluster is for example abcdef.us-east-1.aws.found.io you can add a CNAME my-es-cluster in your DNS which goes to abcdef.us-east-1.aws.found.io.
It will be fully supported in the future AFAIK. But no ETA on this though.