If you use Scoutbook, don’t use Internet Advancement, instead run the unit advancement report from the PO screen as you normally do. There is no reason for units that use Scoutbook to use Internet Advancement. For more information on how to use Scoutbook see the getting started guides here; to print a report for the Scout Shop from Scoutbook, see the guide here.
Internet Advancement is open by default Key 3 members (unit leader, chartered organization representative, committee chair) and those given key 3 delegate or advancement chair access via Organization Security Manager in my.Scouting.org
Organization Security Manager instructions are here: https://help.scoutbook.com/knowledge-base/assigning-a-key-3-delegate-or-other-position-in-my-scouting/