Hi Yair,
Thank you for reaching out. When you use KeywordPlanService to generate the Historical Metrics you are not creating a campaign to run the ads and its only purpose is to generate data so it will not lead to any expense. Let me know if you have any further questions.
Thanks and regards,
Xiaoming, Google Ads API Team
try (KeywordPlanCampaignServiceClient client =
googleAdsClient.getLatestVersion().createKeywordPlanCampaignServiceClient()) {
// Adds the campaign.
MutateKeywordPlanCampaignsResponse response =
client.mutateKeywordPlanCampaigns(String.valueOf(customerId), Arrays.asList(op));
// Displays the result.
String resourceName = response.getResults(0).getResourceName();
System.out.printf("Created campaign for keyword plan: %s%n", resourceName);
return resourceName;
}