You can export contact and deal notes using the API or Zapier. 

Use the API to export contact notes

This option is for advanced users. You need to be comfortable with API calls. 

The /api/3/contacts/{id}/notes API call allows you to retrieve a single contact note based on their contact ID. This API call uses our v3 GET method. For more information about retrieving a contact note,  please see this API document.

To retrieve all notes (contact/deal) in the account, use the /api/3/notes API endpoint and search for the note by its contact or deal ID. This is also a GET method API call, see this API documentation for more information. 

Use Zapier to export contact notes

Another way to export contact notes is to use a tool such as Zaper. You can set up an ActiveCampaign webhook that triggers when a new contact or deal note is added. From there, you can link the webhook to Zapier, which can then map to Google Sheets.