Welcome! This forum has a treasure trove of great info – Scouters helping Scouters! Just a heads up, though - all content, information, and opinions shared on this forum are those of the author, not the BSA.
I have a parent who we are unable to link to their scout. They have a BSA ID and account, when I try to search for them they are not found. When I try to send them a link request from the scout’s page in Scoutbook, they receive the email but are unable to login.
There is a known issue where the connection search function is not finding adults that are not registered as leaders.
The workaround is to ask your Council to make the connection in Akela. The day after the connection is made in Akela, the connection should be added to Scoutbook.