When I try the function like below, it does show the image (found this on an similar question).
function showDialog() {
var ui = SpreadsheetApp.getUi();
// Display a modal dialog box with custom HtmlService content.
var htmlOutput = HtmlService
.createHtmlOutput('<img src=https://i.stack.imgur.com/AuqJU.gif>')
.setWidth(250)
.setHeight(300);
ui.showModalDialog(htmlOutput, 'Script Running');
}
But when I replace the imgur image with one from my shared drive, it doesn't show up (it shows the broken image logo).
The image I'm using is https://drive.google.com/file/d/1uvdBRlfx9C59TTvq8VtVLIpa8u_0B9RN/view?usp=sharing
I've tried to trim it down to https://drive.google.com/file/d/1uvdBRlfx9C59TTvq8VtVLIpa8u_0B9RN/view, but it still doesn't work. I can't find much information about this problem so far, so I hope some of you could help me out!