To connect your HubSpot account, you will need the following:
A HubSpot API key.
Note: The HubSpot lists that will be used in the Email Opt-in module should be all Static Lists.
Get the required Data
Log in to your HubSpot account.
Click on the Profile link at the top right corner.
Choose the Profile & Preferences option.
From the left sidebar, choose Integration → Legacy Apps.
Click on the Create button.
Choose the Private option.
(optional) Fill in the App Details.
Choose the Scopes Tab, and click on the + Add new scope button.
Under the CRM option, select all the available scopes.
Click the Create app button.
Click on the Continue creating button.
Select the Auth tab and from there copy the Access token to your clipboard.
Connect HubSpot with Divi's Email Opt-in Module
Open the Email Opt-in module Settings modal window.
Go to the Content Tab → Email Account.
Select the HubSpot from the provider's list.
Click on the Add button.
Fill in the following fields:
Name - It can be anything you want. For example, you can use
my-hubspot
API Key - Paste the HubSpot API key.
Click on the Submit button.
Choose the HubSpot list you want to use.