HTTP Request with Client Certificate - how to solve this?

Hello,
I have a System that controls most of the lighting and blinds in our house, which is accessible via a HTTP API.
The problem is that it is secured with a Client Certificate, which I have and can use on e.g a phone, but I want to integrate it with HA.
How can I use that certificate (a root cert file and a “.pem” file) in HA on my Pi running HA OS?

Thanks for your support
Aaron Eisele