MagSafe Duo Charger
What do I plug it into besides my laptop. Is there an accessory that plugs into an electrical socket?
iPhone 13 Pro Max
Question marked as
One option: Buy 20W USB-C Power Adapter - Apple
Also see the following from How to use MagSafe Duo Charger with your iPhone and Apple Watch - Apple Support
Use the included USB-C to Lightning cable to plug in your MagSafe Duo Charger to a recommended 20 watt (W) or greater Apple USB-C power adapter* or a compatible third-party USB-C adapter. You can also connect to a USB-C port on a Mac or PC.
* The Apple 29W USB-C Power Adapter isn't compatible with the MagSafe Duo Charger.