If you configured recurring payments (subscriptions), Payrexx will automatically create user accounts for your customers. So your users can administrate the subscriptions and cancel them on Payrexx' site.
Often they don't know where to cancel the subscription. You can provide a link which will directly log them in to your Payrexx page where they can cancel subscriptions, change payment information and more.
The userId for this endpoint will be included in the subscription's webhook.
First your application requests a new authentication link. This means you get a link based on a contact id (param: userId) which you received through a Payrexx Webhook.
You can display the link to your user, or automatically redirect your user. After a click on the link the user will be automatically logged in. This means the customer can then see all fired payments and all subscriptions.