curl --request POST \
  --url https://production.trackstarhq.com/link/token \
  --header 'Content-Type: application/json' \
  --header 'x-trackstar-api-key: <x-trackstar-api-key>' \
  --data '{
  "connection_id": "existing_connection_id"
}'

{
  "link_token": "your_link_token"
}