This only works if you had developer options enabled (and an authorized PC) before the update.
Like many people are reporting, my Nokia 8 also started boot looping after the OTA update (V4.88B). Wiping the phone from the recovery menu fixes the problem, but I had some files that were not backed up and was trying to recover them.
Yesterday, I posted on another forum part of a log that I was able to get using adb, even while boot looping (https://forum.xda-developers.com/nokia-8/help/nokia-8-stuck-boot-loop-camera-update-t3803059/post76825692).
The boot loop problem is related to the WIFI service (migration of legacy configurations).
While boot looping and connected using USB to a authorized PC, run adb shell svc wifi disable. This will disable the WIFI and the phone will boot properly. Don't re-enable WIFI, the phone will crash. Just backup the data using USB and do factory reset, the phone should work properly then.