Move frontend variable for backend api url into the project's configurations.

### Description of the feature request:

Ability to more easily configure the backend API URL without going into the App.tsx file. Similar to how other variables are set in the docker-compose file. I'm not sure exactly how to do that within this architecture, thus the FR and not the PR.

### What problem are you trying to solve with this feature?

Easier deployment outside of same machine (localhost) access.

### Any other information you'd like to share?

_No response_