The right USB implementation for STM32F4 - STM32F7?

[DisruptiveNL]

What is a good design for USB for DFU mode for the STM32F4 (or STM32F7)? I want to connect an application to use DFU in the STM32. The 22 Ohm schematic I do see online in best of bread schematics, but what to do??

https://imgur.com/PtqrAUK

Is it the design at the left or right or are both wrong? I do not get the concept of the 22 Ohm resistors? Why are they needed?