Limitations of Free License API Sync for HRIS Integration

With the free license for a single device, I attempted to connect to the API every 30 minutes to sync attendance data with the third-party HRIS. I would like to clarify the limitations of using the free version. Are there any rate limits or record limits? I have noticed that when syncing every 30 minutes, the data is not consistently updated or reflected in the HRIS system.