Prompt for File Download Location in Chrome
To have Google Chrome prompt for a location to save your files to (e.g. when saving PDF files), click on the Chrome menu on the top right, which looks like 3 dots lined up vertically as shown below. Then in the popup menu click the Settings option.
Scroll down to the bottom of the Settings and click the Advanced dropdown as shown below.
Scroll down further until you see the Downloads section. You need to toggle on the Ask where to save each file before downloading option. The change will be saved immediately and you can cross out of the Settings tab in your browser when done.