In the Video he say this uboats surrendered in Holmestrandsfjorden. That is close to Horten, right south of Oslo.
6 XXI boats surrendered in Horten.
U-2502
U-2513
U-2518
U-3017
U-3041
U-3515
https://uboat.net/fates/surrendered.htm
Anyway, all I wanted to say, cool to see all this XXI in the Norwegian fjords
