"user does not have access to this operation" when following example from documentation

Hello!

As in the title; I have created a master (for all scopes) access token for testing purposes, and following the example from here, I used the following command, where the access token is exported just fine:

export TAILSCALE_ACCESS_TOKEN="$(pass show keys/oauth/tailscale/sylvorg.github/master || :)" && curl -H "Authorization: Bearer $TAILSCALE_ACCESS_TOKEN" "https://api.tailscale.com/api/v2/tailnet/-/devices"

Echoing $TAILSCALE_ACCESS_TOKEN simply gives me tskey-client-...-..., which seems alright, so I don’t quite know what’s going on.

Any help would be greatly appreciated!