How to link a domain to heroku?

Question

Domain Name System

Hello.
There is a domain on 2domains and a server on heroku (the one that is free, free).
Heroku doesn't give an IP (or I didn't find one), but it does have a DNS Target like site.herokuapp.com. The site is available at this address.
Herok writes "Supply this to your DNS provider for the destination of CNAME or ALIAS records."
i created the following entries:
* CNAME site.herokuapp.com
www CNAME site.herokuapp.com
but
@CNAME site.herokuapp.com is not created because CNAME is a record type that conflicts with any other record types if another type of record already exists for the subdomain being searched. For @ by default, there are reference NS records that cannot be removed because they define domain delegation. It is with NS records that CNAME conflicts, and therefore a CNAME for @ cannot be added.
And in my case, all subdomains are linked and www.site.ru too, but site.ru redirects to www.site.ru.
How to be in this case?

Answer 1

No way.
Or look for paid hosting with support for crutches, for some it was called ANAME. Or do it on your own powerdns.

Answer 2

1. Attach the domain to Cloudflare
2. Set Cloudflare DNS for the domain to have a setting that will make your domain an alias for app.herokuapp.com
3. ....
4. PROFIT

Answer 3

https://devcenter.heroku.com/articles/custom-domains
https://elements.heroku.com/addons/pointdns