If you need to connect to the Google Ads API through a proxy, you can do so by setting the proxy property in the CONNECTION section of your google_ads_php.ini file:

[CONNECTION]
; Optional proxy settings to be used by requests.
; If you don't have username and password, just specify host and port.
proxy = "protocol://user:pass@host:port"

For example, you can specify http://user:pass@localhost:8082 as a proxy. Alternatively, you can configure the proxy setting programmatically just like any other configuration setting:

$googleAdsClient = (new GoogleAdsClientBuilder())
    ...
    ->withProxy('protocol://user:pass@host:port')
    ->build();