If you opt to invite your historical customers to leave feedback during the eCommerce plugin registration process, then immediately after installation! 

If you are only inviting new customers to leave feedback, we will send them a request seven days after you have fulfilled their order. You can change the seven-day feedback request delay period via the settings page in your Feefo Hub.

If you change the feedback request delay, any sales that have already been loaded will be sent based on the previous setting and any new sales received following the change will be sent after the new period you have specified.