charging speed from USB QC3.0 to USB-C PD
From your question it's difficult to tell whether you're interested in charging the power bank or charging another device using the powerbank.
Anyway,in order to use USB Power Delivery (USB-PD) or use QuickCharge (QC), both the power source and the power sink must support the same standard (either USB-PD or QC), the same version of the standard and the same voltages. Otherwise, they fall back to standard USB using 5V.
The xtorm web site specifies the capabilities:
Output

1x USB-C PD 60W
1x USB-C 15W (5V/3A)
2x USB Quick Charge 3.0 18W

Input

USB-C PD 60W

So the power bank can provide power to devices using both the USB-C and QC standard. Using QC, it's limited to 18W. Using USB-PD, it can provide up to 60W if the sink device can also handle 60W (probably at 20V).
However, the power bank can only be charged using USB-PD. It cannot be charged using QC. It's probably possible to charge it using 5V, which often goes up to 2A. So you have a charging power of 10W. If you charge the power bank that way, expect it to take 6x longer than using USB-PD at 60W.
Update
According to your comment, you want to charge the power bank using a solar panel. To charge it at the maximum speed, your solar panel would need to support USB PD with 60W, i.e. it needs to talk the USB-PD protocol and it would need to support the power mode with a voltage of 20V and a current of at least 3A.
Quick Charge (QC) won't help as your power bank does not support this protocol on the input.
Charging might also work using standard USB with 5V. It's hard to predict what current would be used in this mode, probably 1A, possibly 2A. It would result in a charging power of 5W (5V x 1A) or possibly 10W (5V x 2A).  As the charging speed is approximately linear to the charging power, charging would take 12x or 6x longer.