The opportunity is: Help me develop a plugin, many hours have passed and I can’t figure it out on my own 
It is based in: I need to create a plugin that takes a configuration value (hence it should have it’s own configuration menu) and taking that configuration value, calculate a new token to be replaced within an email. The calculated token content involves requesting an external API passing a JSON with a custom field added to a contact; the response has the token content.
Remote OK?: Of course.
Salary/remuneration: https://www.buymeacoffee.com/
To find out more: My take on it to kickstart helping me 
https://github.com/leog/MauticAuth0Bundle