Garmin Connect Bulk Export JS v2

/*
A modified version of another pastebin snippet for bulk exporting Garmin data by an unkown author: https://pastebin.com/YN6Gex5R

Here's JavaScript that can be run in any modern browser fairly simply in JavaScript. Might be easier to set up than Python.

You'll want to pre-set a download location in your browser settings to some folder, name it TCX or something, and tell your browser to auto-download there, or else you'll get a ton of popup save dialogs.

First Navigate to the last (most recent) activity you have in Garmin Connect (as in https://connect.garmin.com/modern/activity/5555555555 ), then hit F12 (should work in Chrome/Edge/Firefox; Safari is a little more complicated) to open dev tools to get to the JavaScript Console. Then paste the below code and hit enter to run it.
If you want a different format, change the variable "fileFormat" to the appropriate format acronym if garmin supports it.

It goes from most recent back downloading each one.

Added improvments:
-------------------------
* The script no longer stops if you hit a dead download link. This was always the case for manually added activities.
* No more wait time between individual downloads. The next download starts as soon as it gets Garmin's next activityId.
* Status updates are printed to the console.
* You don't have to specify how many files you want to get. It just stops if it has them all.
* Downloads zip archives with the source data by default. Change `fileFormat` if you want something else.
* The script is no longer dependent on JQuery.

[CODE]*/
const fileFormat = 'zip' // also possible: tcx, gpx - not really sure what else. Zip is the safest bet, as it just downloads the source format.

const activityUrl = activityId => `https://connect.garmin.com/modern/proxy/activity-service/activity/${activityId}`
const nextUrl = activityId => `${activityUrl(activityId)}/relative`
const downloadUrl = activityId => fileFormat === 'zip' ? `https://connect.garmin.com/modern/proxy/download-service/files/activity/${activityId}`
                                                       : `https://connect.garmin.com/modern/proxy/download-service/export/${fileFormat}/activity/${activityId}`

const printStatusUpdate = metadataJson => {
    let date = new Date(metadataJson.metadataDTO.uploadedDate);
    console.log(`Downloading ${metadataJson.activityId}... (${metadataJson.activityName}, ${date.toLocaleDateString()})`)
}

const downloadFile = (url, filename) => {
    const a = document.createElement('a');
    a.href = url;
    a.download = filename;
    a.click();
}

const downloadActivity = activityId =>
    fetch(nextUrl(activityId))
        .then(data => data.json())
        .then(response => {
            fetch(activityUrl(activityId))
                .then(data => data.json())
                .then(printStatusUpdate);

            downloadFile(downloadUrl(activityId), `activity_${activityId}.${fileFormat}`);

            previousActivityId = response.previousActivityId;
            if (previousActivityId !== null) {
                return downloadActivity(response.previousActivityId);
            }
            console.log("This was your last activity. All done. ")
        })
        .catch(console.error)

const urlPathnames = window.location.pathname.split("/")
const initiallId = urlPathnames[urlPathnames.length-1];
downloadActivity(initiallId);
/*[/CODE]*/