Attempting to run dev-server on regtest with a remote node/Esplora backend

Hi there!

I'm looking to fire up the server using a remote regtest Esplora instance hosted in the cloud. The Esplora server works well and is available to outside connections (I can make curl requests to it and whatnot, ports, firewall, etc.) but I'm so far unable to get the block explorer to work with it (getting the old "We encountered an error. Please try again later." screen).

I think I'm probably just missing arguments to my launch command but I have not been able find the info I need so far. Would you guys be able to help me on this? Here is how I currently set it up:

```bash
export API_URL=http://cloudmachineip:60002/
npm run dev-server bitcoin-regtest

# also tried npm run dev-server, doesn't work either
```