Unable to charge HP Envy Intel i7 11th gen with Comsol 25600 power brick

I purchased and HP laptop as above. The battery won't get through a full day on a charge, so I purchased a Comsol power bank. I have contacted Comsol and have been told that it should charge a laptop through USB-C, and HP have indicated that I should be able to charge my laptop over USB. The power bank can provide 100W of power. I am using the USB-C cable provided by Comsol, but I can't charge my laptop with my powerbank. Does anyone have any suggestions how I can charge my laptop with the power bank?

Question by Robert S on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.