Go to your Social Settings
In your HubSpot Marketing Basic, Professional, or Enterprise account, navigate to Social > Social Settings.
Click Publishing then navigate to the "Publish with custom short links" sectionSelect the Publishing tab. Scroll down to Publish with custom short links then click Connect to connect a Bitly account.
Authorize on Bitly
Sign in with your Bit.ly account or sign in with Facebook or Twitter.
Click the Allow button to let HubSpot connect with your Bitly account.
Verify that you've connected your account
You'll be redirected back to the social settings page once you complete authorization on Bit.ly's site. You will then see the Bit.ly account you've connected listed on the page and the custom short domain that will be used for shortened links. Additionally, all of the links shortened by the social media tools will also be stored in your Bit.ly account so that you can access them from there as well.