I need to make a parent a full administrator. He will become scoutmaster in the fall. I am trying to get him ready to take on all of the new things scouting is having us do.
In order for an adult account to get access to Scoutbook as a leader, that adult has to be listed as a leader in Scoutbook.
If the parent is already a leader, you could assign him a Troop Admin position. Be aware that this would allow the parent to have pretty unlimited access to various information, with the potential to make large and sometimes irreversible changes if he isn’t familiar with leader access in Scoutbook.
If he isn’t already a unit leader of some sort, I would start by getting the parent YPT trained, registering him in some adult leader position with council (e.g. ASM), then get him used to Scoutbook from the leader side, before I made him a Troop Admin.
ETA: I would make sure he’s very familiar with Scoutbook before making him a unit admin. It can be pretty easy to foul things up if you’re not sure what you’re doing.