Mobile Apps Conversion Tracking and Remarketing API Always return False

Question

I'm trying to report conversions to the Google Ads API, but it always returns false.

We have tried to notify all users who install our application in a country where we only have Google Ads advertising and it always returns false. We have verified that there are no other MMPs attributing for us (we have disconnected Appsflyer from our account)

This is the request form that we are sending

curl --location --request POST 'https://www.googleadservices.com/pagead/conversion/app/1.0?dev_token=[MY_DEV_TOKEN]&link_id=[MY_LINKID]&app_event_type=first_open&rdid=[ANDROID_USER_GAID]&id_type=advertisingid&lat=0&app_version=2.0.0&os_version=9.3.2&sdk_version=2.0.0&timestamp=1616661257&value=1.99&currency_code=USD' \
--header 'Content-Type: application/json; charset=utf-8' \
--header 'X-Forwarded-For: 216.58.194.174' \
--header 'User-Agent: MyAnalyticsCompany/1.0.0 (iOS 10.0.2; en_US; iPhone9,1; Build/13D15; Proxy)' \
--header 'Host: www.googleadservices.com' \
--header 'Content-Length: 0'

Following the format specified in the documentation https://developers.google.com/app-conversion-tracking/api/request-response-specs

Has anyone had this problem? What am I doing wrong? Regards!