If you receive the error message “We were unable to authenticate your request” when trying to connect Sales Insight Actions to Salesforce, there might be a restriction on your access to Salesforce’s API. Check with your Salesforce Admin to make sure the following things are in place.

Enable API in User Permissions

Have a Salesforce Admin log into SFDC.
Select Setup.
Select Manage Users.
Select Profiles.
Find the Profile that the ToutApp users are under and click Edit.
Scroll down to Administrative Permissions and make sure API Enabled is checked.

Check if Salesforce is Blocking Sales Insight Actions from Connecting

Have a Salesforce Admin log in to SFDC.
Select Setup.
Select Manage Apps.
Select Connected Apps OAuth Usage.
Make sure that Sales Insight Actions shows “Block” next to it. If you see “Unblock”, click the button to unblock Sales Insight Actions’ access to Salesforce.