Using an image in the assets I have it working here:
I used my ImageBase64 extension to get the base64String from the optimised image displayed in the image component
Script as follows:
function doPost(e) {
var data = Utilities.base64Decode(e.parameters.data);
var blob = Utilities.newBlob(data, e.parameters.mimetype, e.parameters.filename);
var fileID = DriveApp.getFolderById(e.parameters.folderId).createFile(blob).getId();
return ContentService.createTextOutput(fileID);
}
