Hi,
You will want to use your own custom domain with Front Door.
When you create front door, you can specify a name and it will add a uniquifier to it. For example, if you gave it a name of "hampton123", the endpoint name it generates would be something like hampton123-n0a5cfys3awopma.z01.azurefd.net.
You can't customize this after it has been created. You could add a new endpoint, but again it will add uniquifier to it as described above.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP