First, navigate to the campaign where you'd like to connect the Vendasta integration, then click "Integrations" from the menu on the left side of the screen.
Click on Vendasta in the list of available integrations.
Then click Connect New Account.
In the window that appears, enter the API User and API Key for your Vendasta account. If you're not sure where to find those credentials, please contact Vendasta support. Once you've entered your credentials, click "Save".
Next, select the client you want to connect and click "Save".
If the client that you would like to connect is under a different Vendasta account, you will need to enter different credentials to access that account. To do so, click the button that says "New Account" and follow the above steps.