I bought a myapp.app domain with OVH. I've also bought a Heroku hobby dyno in order to have a secure subdomain for my api (https://www.server.myapp.app instead of https://www.myapp.heroku.app).
In Heroku's dashboard/settings, I've added the domain server.myapp.app and copied the generated DNS target provided by Heroku. It looks like: hello-world-5fghjofz765h.herokudns.com.
Then, I added a CNAME record in OVH's DNS zone panel. The name is server.reapr.app. But when validating the entry, I notice the generated domain has an additional . in the end: server.reapr.app.
Is it normal? Should I enter the same name with a final dot in Heroku too?
Next. I added a CNAME record in my DNS zone panel.
When copy/pasting the DNS target in ovh, ovh claims that this is a relative notation that will point to hello-world-5fghjofz765h.herokudns.com.myapp.app..
They say I can add a . in the end to make this notation absolute and point to hello-world-5fghjofz765h.herokudns.com.. I don't understand what it means.
In any case, the DNS target is not strictly equal to the DNS provided by Heroku. There is either an additional . or a myapp.app. in the end of the url.
Anyway, I've tried both options. In each case, Heroku says they're unable to resolve DNS for server. The final error is: 1 domain failed validation.
How to fix this? I'm paying for a dyno I can't even access.
EDIT:
The ovh DNS Zone. I own the domain www.myapp.app (myapp is a random name for this example, and is hidden by a black rectangle on the images below).
The heroku subdomain settings:
