If the Salesforce plugin disconnects, due to a change in permissions of the Salesforce admin who initially connected the plugin, or if you'd like to modify which user authorizes the plugin, the plugin will need to be reconnected with the Salesforce admin's Salesforce credentials. Before connecting, make sure the Salesforce profile matches the integration permission requirements.
An Outreach admin will go to settings > plugins. On the right side of the Plugins page, hover your cursor over the Salesforce Plugin and a drop-down arrow will appear. Click on: Reconnect > (User's Name) > Authorize.
To verify the authorization has been made, run a test by applying a change to a record within Outreach and then checking to see if Outreach has made the update in Salesforce. You can manually sync the record to speed up this process.