Lightspeed + Trustpilot AFS integration automatically sends  review invitations via email to your customers after they make a purchase or have a service experience. When a customer purchases something from your business, you send them an order confirmation via email. You can read more about AFS here. 

If you want to use AFS with Lightspeed, you’ll need to go to your Advanced Settings in Lightspeed and add your unique Trustpilot email address.

1. Go to Settings > General Settings > Advanced.

You should see an option to Set a Feedback BCC E-mail.

2. Enter your unique Trustpilot email address.

You can learn more about Lightspeed Advanced Settings here: https://ecom-support.lightspeedhq.com/hc/en-us/articles/220661207-Configuring-general-settings-for-your-online-store

And if you want to learn more about AFS, have a look here.