Monitor with usb-c doesn't charge the laptop

I got a monitor with an usb-c (displayport, power delivery and usb-hub) but it won’t load, while plugged in. Only the displayport and usb-hub devices work. On Windows 10 everything work perfect, so I think the problem doesn’t come from the monitor itself.
Laptop: Thinkpad E14 Gen 2
Monitor: LG 35WN75C-B
Kernel: 5.7, 5.8

Does power delivery work probably when plugged via usb-c wall charger?

Yes it does

I’ll ask what somebody else asked elsewhere:

Yes they are both listed. I tested it with the live usb boot and it works. I will probably reinstall and hope it works then as well.

I suppose that you need thunderbolt device authorization as described in wiki page wiki.archlinux .org/index.php/Thunderbolt (sorry, as new user can’t add link).
It can be done using GUI after installing plasma-thunderbolt package (reboot was needed in my case to see Thunderbolt item in System Settings) or using boltctl from command line.