Is there a way to add a deleted account back to Dash?

If you've deleted an Amazon account connection from dash via the Account Manager, you will need to re-add and re-authenticate the account as you would to add a new account. For security purposes, we do not leave the connection to the account open once you've deleted the account in dash but we do preserve the related merchants' data. So, if you re-add the account, dash will pull the previous 60 days of data for all related merchants and data pulling will resume on top of the existing historical data.