How do I sign out of Amazon Prime Video on all devices at once?

To sign out of Amazon Prime Video on all devices at once, one must use the web interface through a browser. By visiting the Amazon website and navigating to the "Accounts & Lists" section, followed by "Your Account," there is an option for "Prime Video Settings." Within that section, under the "Registered Devices" tab, there's the ability to manage all devices connected to an Amazon account. This includes the choice to deregister devices individually or altogether. If an option to sign out of all devices simultaneously is not visible, deregistering each device will accomplish the same goal of logging out from Amazon Prime Video on all devices at once.