Hi,
It seems that you were not able to receive my private messages.
My apologies for the delayed in response as I was discussing this with the team.
The reason you are encountering the error CAMPAIGN_CANNOT_SET_MORE_THAN_ONE_CONVERSION_TYPE_ID is because there are some campaigns that can only support 1 conversion type IDs. If you want to know more details on how to set more than 1 conversion type Id, you may contact the product support team as this is more of a product related concern. You can reach out to them by opening your concern in the
AdWords Community Forum.
Regards,
Dannison
Google Ads API Team


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