I responded to your email about this, but all of our API Keys are customer-managed and available here:
Any integrations that require their users to obtain their own API Keys should be asked to use one API Key for all of their users, to avoid unnecessary work for people who want to use their integration. Feel free to have them contact us here or at email@example.com. We're happy to increase API rate limits for any applications that hit their limits (and are making sensible calls to us).
Partner API Support Engineer