Keeping a Message Review in your account
On a paid plan you can save a Message Review to your account and open it again later, from a browser you have added.
A saved Message Review is encrypted to the devices you have added, and adding a browser needs your sign-in and the device code we email you. That is what lets you reopen it on that computer.
There is a cost to that design, and you are asked to agree to it before the first save: if you lose access to every device you have added, you lose access to a saved Message Review, and we do not recover it for you. Clearing a browser's stored data, or using a private window, loses that browser's key. A phone you have added still opens it.
You can delete a saved Message Review whenever you want, and deleting it removes the stored copy.