Regenerate SSL certificates when updating hostname

[ShurikAg]

I have one subdomain configured for my host and mapping (for testing). Everything worked created there.
So, I decided to switch to the real prod URL: apii.priz.guru -> api.priz.guru

I am using the automated process, so once changes were pushed, I switch the DNS to point to Ambassador. It was switched, but now the certificate is invalid. How do I force regenerate the certificate?

[ShurikAg]

As I understand, it looks like I need to create a wildcard certificate following these instructions.

Also, looking back at the details of how to configure it, it looks like these instructions are built for domains managed in DO.
In our case our domains are in CloudFlare (and it's important to leave them there).

Where can I find information of how to correctly configure wildcard cert with automation?