Guidance on using Letsencrypt wildcard made live few days back with subdomain

The main hurdle to get over with wildcards is that you need to be able to automate DNS TXT record changes to your domain. Does your DNS host ( provide an API of some kind for updating records?

If not, you will probably be better off just using a non-wildcard certificate that has your main domain and subdomain on it

You can read about how to use Certbot to get wildcards here, if you are still interested: Getting wildcard certificates with Certbot