If you wish to change the status of Guest Customers to Active Customers, then follow the steps outlined below:

In your Loyalty dashboard, go to More > Advanced Setting > Guest Customer Settings and enable the toggle.

Note: Be aware that upon enabling, guest customers will get immediate access to your platform's functionalities, even if they do not have an account in your store.

If you do not wish to activate all the customers then, you can activate only a few even only a single customer.

Go to loyalty > Customer > Customer ID > Actions > Edit Customer > Status > Active

As soon as you click on the update button after selecting the status, it will activate that specific customer.