You need to be 'Super Admin' in Hubspot to be able to grant Stacksync access to Hubspot.
This is because only the 'Super Admins' have the OAuth scope which is required to connect your Hubspot to an external service such as Stacksync (more infos ).
1. Click "Create new sync"
2. Select the HubSpot connector
Getting stuck on this step?
If you get stuck on a loading page after when trying to connect HubSpot (i.e. waiting a few minutes), verify that you do not have an Ad blocker or that popup windows are not blocked.
Fix ✅: Press cancel, Deactivate your Ad blocker and try again to Authorize HubSpot.