Here is an implementation guide for your reference
https://www.cisco.com/c/dam/en/us/products/collateral/security/esa-spf-dkim-dmarc.pdf
All DNS records would be published by your local DNS team or ISP depending on who takes care of the DNS records.
You can contact TAC to confirm what needs to be included in the SPF records for your cloud ESA allocation, however the records themselves are published on your DNS side.
Regards,
Libin Varghese