This is a post I made in another similar thread, might help you sort it out.
Charging Lipo batteries with Pico Lipo - Support - Pimoroni Buccaneers
Wired up my Amigo Pro to a Pico W setup.
With just the GND, and VDEV wired to VSYS, battery state of charge is displayed. Not sure its correct though? It’s seems to be stuck at 50%. And no way of knowing if its being charged, other than the indicator on the Amigo Pro. There is no detection of power being applied to the Amigo Pro via the python code. Battery will only charge if power is being feed to the Amigo Pro USB C jack. The On Off button on the Amiga Pro works. Need to do more testing in this mode to see if the code needs to be changed?
If I also wire up the +5V from the Amigo Pro to VBUS, the charging indication function works. And my battery state of charge now shows 90% when running only on battery. Which is about right, as it was fully charged when I put that battery in storage. Battery will also be charged if you power the Pico W via its Micro USB Jack. The ON Off button only works when “only” on Battery Power though.
EDIT: Charging LED turned off while I was typing this post
EDIT: 2
After running about 4 hours battery state went down to ~60%. That’s about right I think. It’s running a PICO W, two 320x240 LCD’s, and a couple of i2c breakouts. It’s one 2200 mAh battery, and I haven’t run this setup from battery before. Not for any length of time anyway. Just to test my code.