Head over to your Workspace > Project > Integrations. Click on Hubspot Integration.
Enter the information requested, log in to your Hubspot account and click on Next.
Select the streams you wish to extract and click Finish.
Check the Hubspot data source by opening the Integrations section and clicking on Hubspot. The icon next to the Integration's name will change from red to orange or green to indicate if it failed, is in process or is active, respectively.