Update Shipping Notification on a Mercari Generated Shipping Label?

I've never gotten this action required message before, anyone know what I should be doing?

I used a Mercari generated label and the tracking says it should be delivered today so I don't understand why it says I need to contact the carrier or cancel it.

I've never gotten this action required message before, anyone know what I should be doing?

I used a Mercari generated label and the tracking says it should be delivered today so I don't understand why it says I need to contact the carrier or cancel it.