Issue
You have a Lead in Salesforce that's synced to your Postgres database using Heroku Connect, and you'd like to convert the Lead into an Account, Contact, or Opportunity.
Resolution
Converting Leads is an involved process in Salesforce. If you need to do the lead conversion programmatically, we strongly recommend that you do the conversion in Salesforce and then allow Heroku Connect to sync the converted leads instead of implementing the logic directly in Postgres or your application.
You can programatically convert Leads in Salesforce with either Apex or the SOAP API.