Do anyone know how to do the DNS validation update for sitelutions.com?
You may be able contact their support and ask them (looks like they have a SOAP based api?) how to script TXT record changes. Assuming you have the subscription level required they will probably help you, I assume. You’re looking for a way to script it using cURL or similar.
Alternatively check out the acme-dns API, you can either hsot your own acme-dns server or use the suggested default, then you create the CNAME it tells you to then continue the request.