Get DKIM with API is possible?

Hi
I've external DNS service, and I need to set the DKIM record for mail service for domains (not one)
I know that I can:
go in plesk,
search the domain,
select the domain,
select the MAIL tab,
select mail settings,
enable the DKIm flag
apply the change
click the "external DNS" link
copy the DNS record.
And then modify my external DNS service....

There is no API to enable DKIM and get the DKIM record??
Thanks