Thank you!
Good power bank at a good price. The USB C is, in fact, an input/output port : you can charge the power bank with it (input) or charge your device (output). For exemple when I charge my my Xiaomi Mi A1 (QC 3) or my Ipad Air (PD) the power bank displays 5V 2.4A. For now I did not success to get the 18W working, I will try on other deviced.