Hi Golnoush,
Sorry for the confusion. That field is intended to be selectable with
display_keyword_view, but it currently is not. I'll follow up on updating our documentation.
In the meantime, if it's helpful you
can retrieve campaign.bidding_strategy (the resource name of the bidding strategy) and campaign.bidding_strategy_type with
display_keyword_view.
Thanks,
Josh, Google Ads API Team

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