Yes, it works. It has a USB-A connection. You can also use a USB-C to Lighning cable. Then it charges faster. There is also a not too cheap cable from Xtorm, with which you can attach the cable directly to the power bank: Xtorm USB C - Lightning (0.10m)

However, I can't recommend this expensive cable if you have to use it to charge your iPhone in a bag when you're out and about. It will break too quickly. You're better off buying a USB-C Apple original Lightning cable: Apple USB-C - Lightning cable (1m)

Unfortunately, there is no 0.5m with USB-C, only with USB-A.

But as already said, charging via USB-A socket also works and is fast. They are Quickcharge certified. I can't say how fast because I don't have an iPhone 7, but a 12 Pro. And I charge it almost exclusively via Macsafe. I also bought the Xtorm FS400 Macsafe powerbank. I use the Voyager to charge my Surface Book 3 via the 60W output and that is fast enough.

I hope I was able to answer your question.