You can add any quantity of accounts for promotion. But note that balance for each account deducting separately.
Use the button “Add account” on the panel control.
In some cases, you need to confirm to add an account; where the system will warn you about. You need to go to your Instagram account from your phone and confirm that you just have entered to your profile.
Rarely when adding an account password resets. Nothing wrong. Just change your password and try again. This can happen only once while adding an account.