You're passing incorrect arguments to batch.Download.ImageCollection.toDrive. The first argument needs to be the ee.ImageCollection; you're providing a JavaScript object literal. The function tries to call ee.ImageCollection.size on something that is not an ee.ImageCollection. The export should be more like this:

var ops = {
  scale: 30,
  region: an_extent,
  maxPixels: 1e13,
}

batch.Download.ImageCollection.toDrive(col, 'folder_name', ops)

You're passing incorrect arguments to batch.Download.ImageCollection.toDrive. The first argument needs to be the ee.ImageCollection; you're providing a JavaScript object literal. The function tries to call ee.ImageCollection.size on something that is not an ee.ImageCollection. The export should be more like this:

var ops = {
  scale: 30,
  region: an_extent,
  maxPixels: 1e13,
}

batch.Download.ImageCollection.toDrive(col, 'folder_name', ops)

You're passing incorrect arguments to batch.Download.ImageCollection.toDrive. The first argument needs to be the ee.ImageCollection, you're providing a JavaScript object literal. The function tries to call ee.ImageCollection.size on something that is not an ee.ImageCollection. The export should be more like this:

var ops = {
  scale: 30,
  region: an_extent,
  maxPixels: 1e13,
}

batch.Download.ImageCollection.toDrive(col, 'folder_name', ops)

You're passing incorrect arguments to batch.Download.ImageCollection.toDrive. The first argument needs to be the ee.ImageCollection; you're providing a JavaScript object literal. The function tries to call ee.ImageCollection.size on something that is not an ee.ImageCollection. The export should be more like this:

var ops = {
  scale: 30,
  region: an_extent,
  maxPixels: 1e13,
}

batch.Download.ImageCollection.toDrive(col, 'folder_name', ops)