Feature Request - API Endpoint For Retrieving Generated TLS Certificates

Is your feature request related to a problem? Please describe.
I would like a central place that performs DNS challenges to generate TLS certificates, and be able to retrieve them by my other services programmatically through an API.

Describe the solution you'd like

I would love it if there was an additional endpoint whereby I could retrieve the generated TLS certificates.

It seems that Nginx Proxy manager has done 99% of the work, with a fabulous UI, and already has an API with an OpenAPI spec. Other's have requested the ability to download the certificates, but I believe they are referring to doing this through the web UI, rather than through an API request.

Describe alternatives you've considered

I've looked for other open source solutions out there that provide the ability to generate TLS certificates through DNS challenges and expose an API for downloading them, but have so far been unable to find one. I am considering writing my own service to do this, but it just seems like a shame to almost re-invent the wheel when Nginx proxy manager has done 99% of the work and has integrations with loads of the DNS providers (cloudflare etc).

Start by reviewing the existing API and its OpenAPI specification to understand how generated TLS certificates are represented and exposed. Trace the certificate-related API entry points and determine the expected retrieval behavior, including what “done” means for programmatic access; the issue does not name specific files or tests.