Where can customers see their subscriptions?

If you customer has an account in your shop, then the customer will be able to view subscriptions by logging into their account and going to /a/subscriptions/manage URL in your shop. If the customer doesn't have an account in your shop, then they can still view, edit and cancel their subscription through the link they receive in each subscription email.

You can try to automatically add this link in the Installation section of the app settings. If for some reason, the automatic installation doesn't succeed, then you can also manually add the link to your theme Liquid files.
You can follow our instructions on how to manually add the link to your account menu here: https://www.sealsubscriptions.com/articles/add-link-to-subscriptions-list.

Customers can also access their subscriptions by requesting an email with a magic link which leads to all of their subscriptions. The form where they can request such email is accessible on /a/subscriptions/login if you enable it in Seal Subscription -> Settings -> General Settings.

When customers create a subscription, they also receive an email with a magic link, which they can always use to access their subscription. Just make sure that you have this email notification turned on in Seal Subscriptions > Settings > Notifications.