If the user does not have Admin rights to the Business Manager account that owns the Business Page, Targetable will not be able to connect to your Business Page.
If the user does not have Admin rights to the Business Manager account that owns the Business Page, Targetable will not be able to connect to your Business Page, and the user will receive the following error message from Targetable:
To address this issue, please contact an existing Admin on the Business Manager account to obtain Admin access to the Business Manager account.
Depending on your current permission level on the Business Manager Account, you may be able to find a list of existing Admins on the Business Manager account by following these instructions:
To find the name of Business Manager Account and current Admins:
1. Return to your Facebook Business Page and click on the Settings link towards the upper-right corner of the browser: 
2. In the Settings menu, click the Page Roles link: 
3. Depending on your current level of access to the Business Manager account, a list of individuals who have Admin access to the Business Manager account may be displayed in the Page Roles menu as shown below:
Only current Admins on the Business Manager account can grant Admin access.
Current Admins can change your permissions by following these instructions:
To add a new user as Admin to Business Manager Account:
1. Go to https://business.facebook.com and select the Business Manager account that owns the page.
2. Next, click on Business Settings:
3. This will open a new window. On the next page, while People is highlighted, click the +Add button:
4. In the Invite People window that appears, enter the user's email address and assign them Admin rights by toggling Admin access to On, and then click Next: 
5. On the next page, while Pages is highlighted, select the Business Page and assign the user Admin rights to the Business Page by toggling Manage Page to On, as below:
6. Before you click the Invite button, proceed to grant the user Admin rights to the Ad Account by clicking on Ad Accounts in the Select Asset Type column, then selecting the Ad Account and toggling Manage Ad Account to On, as below:
7. Click the Invite button to send your invite to the new user.
To upgrade permissions to Admin for a user already added to the Business Manager Account:
1. Go to https://business.facebook.com and select the Business Manager account that owns the page.2. Next, click on Business Settings:
3. This will open a new window. While the People link is selected, find and select the user whose permissions need to be upgraded to Admin and click the Edit button towards the upper-right:
4. In the new window that opens, click the Business Manager role dropdown menu and select Admin instead of Employee and then click the Update Person button:
5. You’ll be returned to the Page Roles menu. Here, make sure the user is selected again and then click the Add Assets button: 
6. On the next window that opens, select Ad Accounts, and then choose your Ad Account. Toggle Manage Ad Account to On for the user, and then click the Save Changes button, as below: