Hi Paolo,
Have a look here:
How to use DNS API: https://github.com/acmesh-official/acme.sh/wiki/dnsapi. Most API key providers, and how to use them, are listed there.
EDIT:
If your DNS provider doesn’t provide API access, you can use our DNS alias mode:
https://github.com/acmesh-official/acme.sh/wiki/DNS-alias-mode.
Michel-André