I've got a laptop with HDMI output that I'm trying to connect to my projector with VGA input.

I've got a VGA cable, as well as a dongle that says this in the online description: "This product is a portable digital-analog conversion line, defined through a standard HDMI input HD sources, you can convert HDMI video output to VGA"

It's not working. Have I got the right HDMI to VGA cable? Is it just that my VGA cable is faulty? I don't have any VGA-output devices that I could test the VGA cable with.

The projector works well when just projecting the "no signal" screen, or the menus, so it's not a matter of a broken projector (although maybe it's a broken input?)

I'm just trying to figure out whether I have the right dongle. This is the one I have:

https://www.amazon.co.uk/gp/product/B009CRN810/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1