Go to Business Settings in your Facebook Business Manager account.
2. Then navigate to Data Sources > Pixels > Click on the Pixel and then click Add People
3. Click the account you want to use and turn on “Manage Pixel”, then click Assign.
4. Click “Add Assets”.
5. Select the Ad Accounts you want to assign your Facebook Pixel to.
6. Click “Connected Assets” to see the Pixel connected to the Ad Account.
7. To check which Pixel ID is associated with your store use the Pixel Helper tool and these instructions.