Let's Debug

Test result for southcentralus.cloudapp.azure.com using http-01

Fatal
No valid A or AAAA records could be ultimately resolved for southcentralus.cloudapp.azure.com. This means that Let's Encrypt would not be able to to connect to your domain to perform HTTP validation, since it would not know where to connect to.
No A or AAAA records found.
Error
southcentralus.cloudapp.azure.com is currently affected by Let's Encrypt-based rate limits (https://letsencrypt.org/docs/rate-limits/). You may review certificates that have already been issued by visiting https://crt.sh/?q=%azure.com . Please note that it is not possible to ask for a rate limit to be manually cleared.
The 'Certificates per Registered Domain' limit (50 certificates per week that share the same Registered Domain: azure.com) has been exceeded. There is no way to work around this rate limit. The next non-renewal certificate for this Registered Domain should be issuable after 2020-05-18 17:29:09 +0000 UTC (2m0s from now).

Submitted May 18 17:26:03 2020. Sat in queue for 2ms. Completed in 6s. Show verbose information.