Ssl certificate error at a new custom subdomain

Hello, I am really new to openedX and Tutor. Thanks in advance for any help into the right direction!

I installed openedX via tutor. I can enjoy the platform at my_url.com and studio.my_url.com. Now I want to make a custom site which I want to make via the admin with admin/sites/site/. However this new site gives an SSL_ERROR_ on new_site.my_url.com. I made A and CNAME records that ultimately points to the server’s IP address

C NAME RECORD: *.my_url.com → my_url.com
A RECORD: my_url.com → server IP address

What I think to understand is that Caddy takes care of generation certificates in real time. I think that I have to search in this area for a solution, but don t know how to proceed.

Any help is very much appreciated.