Here are the steps to update your Pixel ID:

• Go to the Setting tab. And then select Accounts.
• All the connected accounts will appear on the screen.
• Click on the Edit option next to Pixel ID. 
• An Edit Pixel confirmation screen will appear.
• A complete drop-down list of all the Pixel IDs will appear. Select the Pixel ID you want. 
• Click on ‘Save Changes,’ and your Pixel ID will be successfully updated. 

Note: Please make sure that you have selected the same Pixel ID for your Buy with Prime console, website, and app.