curl --request GET \
  --url https://api.tally.so/forms/{formId}/analytics/metrics \
  --header 'Authorization: Bearer <token>'

{
  "visits": 123,
  "visitDuration": 123,
  "submissions": 123,
  "uniqueRespondents": 123,
  "totalViews": 123,
  "starts": 123,
  "completions": 123,
  "completionDuration": 123,
  "completionRate": 123
}