## The problem
Reported in PostHog Feature Flags: Google Ads destination.
## The fix
Setting up the PostHog Google Ads destination? The confirmed gotchas from the thread:
1. Create the conversion goals in the same Google Ads account where the campaigns live. Otherwise you get 'the click ID is associated with an Ads account you do not have access to'.
2. Newly created conversion actions can take up to 6 hours before Google lets you import conversions into them. PostHog does not retry failed requests, so wait and use the testing tab to resend events.
3. You do not need a gclid filter; the destination already skips events without a valid gclid.
4. If gclid is empty, use a frontend event instead of a backend event, since gclid comes from the browser.
5. The 401 'invalid authentication credentials' errors in early 2025 were a PostHog environment-variable migration bug, fixed server-side; users confirmed calls started succeeding again.