To update a member's email address in your loyalty program, you'll need to update their contact details in your Shopify admin.
How to update a loyalty member's email address
1. In your Shopify admin, go to Customers
2. Find the customer whose email address you want to change and click on their name
3. On their Customer page, under Contact, click Edit
4. In the Edit Customer window, you can edit the Email address field to update or amend mistakes
5. Click Save to finalize changes
The updated email address will sync to the member details in your loyalty app admin.