Hello, @9130349822154186.
Thank you for posting here in the Community. I'd like to share how your user can access the Apps feature in QuickBooks Online (QBO).
In QuickBooks Online (QBO), there are different user types by QuickBooks Plan. Each type has different access. If a user is added as a standard user, the user granted can work with customers, sales, vendors, and expenses. Also, you can enter timesheets, add users, update company info, or manage subscriptions depending on the level of access he/she is granted.
On the other hand, only users who have master and company admin privileges will be able to subscribe to an app. There can be only one active connection per app per QuickBooks Online company.
Additionally, check out this article to learn more about the different user types: User roles and access rights.
To learn more about user types as well as adding and removing users access, you can check out these articles: Add, delete, or change user access
You can also read this article for your future reference about changing the QBO master admin user role: Change your QuickBooks Online master admin user.
Leave a comment below if you have any other questions. I'm a post away to help. Have a good day!