If you are getting uid===-1 on the /api/config route it means your request was classified as a spider. https://github.com/NodeBB/NodeBB/blob/master/src/routes/authentication.js#L38
Adding support to Google Maps API
Under what heading in plugin.json shall I specify the link to this external third-party script:
Also I do not want the API key exposed to the end users of the resulting HTML file.
To further clarify, the order of sequence of execution of scripts should be ...