In order to connect an app to QBO, you need to have admin-level rights within that QBO company. This is requirement from Intuit/QBO.
As an alternative to connecting directly to QBO, you can also export a pair of reports and import those into Tallyfor via the QBD tab.
Here's a resource to help with that: https://support.tallyfor.com/article/8-how-to-get-the-right-quickbooks-desktop-reports
To change the user type in QBO, go to the Gear Icon/Manage users/
Find the user you want to edit and select the Edit dropdown.
Under User type, change the setting to "Admin"
If another admin has connected to the QBO company, you may be asked to Change Admin. It is ok to click "Change Admin" to proceed.