Make sure the Campaign ID is correct and belongs to the correct account.
How to Verify Campaign ID Configuration
Go to CRM > Campaigns.
Find your campaign in the list — the Campaign ID is displayed in the first column of the table.
Confirm this ID matches exactly what you are using in your API requests.
Common Campaign ID Issues
Wrong Campaign ID: Using a Campaign ID from a different campaign or account.
Account Mismatch: Campaign ID belongs to a different account than your API key.
Campaign Status: Campaign associated with the Campaign ID is inactive or suspended.
Format Errors: Incorrect formatting or extra characters in the Campaign ID.