cannot start ff client id starts with digit

Say my GitHub app’s credentials would be as follows

- client id: `012def`
- secret: `abc456`

If I try to start the app like this:

```
012def=abc456 npm start
```

I get error

```
bash: 012def=abc456: command not found
```

Is there anything I can do?

Start by reproducing the documented `012def=abc456 npm start` command in bash and inspect the npm start entry point. Determine how credentials are passed when the client ID begins with a digit; done means the application starts successfully with the example credentials.

Written by the indexing model from the issue text.