Hi,
Using the API, you can only set the
bid adjustments for a given criterion. It might not be possible to enable them conditionally. You could perhaps consider setting the targeting for other criterion too so that your ads will only be served in those cases. Since this is a product level question, you could also post this on the
advertisers community forum. The product experts there might be able to suggest some alternate options.
If your question is not about conditionally setting the bid modifier, could you please elaborate?
Thanks,
Sreelakshmi, AdWords API Team