Can I send a request to remove a particular installation (device) from my backend Node.js server?
There are 2 ways you could do it, here are the modules:
https://www.npmjs.com/package/unifiedpush-admin-client
This implements the endpoint here: https://aerogear.org/docs/specs/aerogear-unifiedpush-rest/#-2081373521
OR
https://www.npmjs.com/package/unifiedpush-registration-client
This implenents the endpoint here: https://aerogear.org/docs/specs/aerogear-unifiedpush-rest/#417932897
The second option probably has slightly less config