Hi we are trying to build an extension by integrating our APIs. For example take info from contacts from hubspot and use it as merge data and get a merged document. Any info regarding building extensions would be helpful.
Should I do this only using CRM Development Tools or it there any other way?
Additionally, just to try how this works we tired an existing app from github downlaoded it and tried executing, we started executing in terminal and it opened a localhost page given in the code, and asked us to instal the app, once we clicked that, it asked us to login, and showed us this page, how idea what this means?
