Hello Dima,
In order to fetch all the campaign budgets and the campaigns associated to them you can use campaign_budget resource name and can use the below query for example.
Query: "SELECT
campaign_budget.id,
campaign_budget.name,
campaign.id, campaign_budget.amount_micros, campaign_budget.period FROM campaign_budget"
The v2 is the latest version of Google Ads API, you can upgrade to that version from the client libraries
here.
Here is the guide to migrate from v1 to v2. Please give it a try and let me know if you have any further questions.
Regards,
Sai Teja, Google Ads API Team

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