Aperture 3.6

Hi, I'm using Big Sur and still have the old Aperture on my Mac but obviously not working. I have an old Aperture backup of about 460GB on an external drive. I need open this to export the images to my cloud. However, my Mac wants to convert the library to Photos which looks like it will take a day and my Mac (if leaving it overnight) want to go into a shut down or sleep mode, even when trying to do everything to keep the Mac on. And it's so slow. Also, I only have about 250GB available on my MAC. It would be better to have a version of Aperture to open the library and export the images but I presume I'd need an older Mac & OS. So just looking for any help and ways of getting my images off this Aperture Library? :)