How can I access a Realm Configuration property's value from Unity and/or microservice code?

I added a new config property in the Realm Configuration portal to store some API key, I need to access its value from Unity and/or microservice code. I've looked through the documentation but I can't find any reference to it.

As far as I understood you can use Realm Configuration properties for this kind of scenario right? Or do you recommend another method to store sensitive data and use it from Unity and/or a microservice?

Thanks in advance!