There are plenty of power banks on the market that can charge your smartphone on the go. Unless you invest in a wireless power bank, you will need to bring your own cable to connect your phone. The Infinity Lab Instant Go 5000 takes care of that problem. It has a built-in Lightning cable. With 18W Power Delivery 3.0, it can charge your iPhone 12 a whole lot faster.
This power bank is MFi certified. It has enough juice to give your phone one full charge. A USB-C version is also available. You can find out more here.