PD = USB-C Power Delivery. The 20 watt one in the Apple Store is PD but there are many with the same technology so even let’s say Anker or Spigen USB-C PD charging brick works.

I use apples 20 watt brick on my past 4 iPhones. It’s 0-80 in about 40-50 minutes or so then the last 20% trickles for about an hour to hour and a half till 100%.