For my CA I got DIGICERT (https://www.digicert.com) thru the MVP Program and got the SAN Certificate that can be used on multiple domains.
A free alternative will be Let’s Encrypt (https://letsencrypt.org/) however you may need to use an Azure Site extension for this.
I got started with Digicert by signing-up and then do the verifications. For me I was asked with only two requirements:
- I have a currently active government issued photo ID (Suggest you don’t black out the address) that has your name, address and expiration date.
- That you have control or ownership of the domain – They will send a link thru your postmaster emails. Be sure to check if these are active.
I must mention that they have a phenomenal customer service and will follow-up thru phone and email on your certificate order and help you on the requirement.
After the verification they will send you an emails confirming the verification. Got a personal email from an Engineer and the automated email. Mine just took a few hours after I did the requirements and I was able to continue with creating a CSR.