Meaning of FIT fields in ECG FIT files

For FIT File Viewer, I would like to find the meaning of the various messages in an ECG FIT file. I can do this using some sample files, but I don't yet have a suitable Garmin device yet. Therefore, could some of you share an ECG FIT file?

You have to export your wellness data, see https://support.garmin.com/en-US/?faq=W1TvTPW8JZ6LfJSfK512Q8 In the ZIP file that you receive, there should be an ECG FIT file.

Then go to the website (www.fitfileviewer.com), upload the ZIP file and select the ECG FIT file (or extract this FIT file yourself and upload it). At the bottom of the page, click on 'Contact me', and send it.

I will use the data only to find out the meaning of the fields, your data will not be shared with anyone. Also, you send the data anonymously if you don't fill in the name and email address.

Thanks for your help!