can i download older version of imovie

Only if you had previously downloaded iMovie using your AppleID.

If you have open the App Store, sign in and click on Purchased,

this will list all apps you have downloaded, if iMovie appears

click on Download and it will download the correct older version of iMovie

for the OS your older mac is using.

I have tried that with no luck, it shows on the App Store that I have previously purchased it and when I click on the little cloud with the arrow it tells me I need to update to a newer version of macOS, doesn't support Catalina and I see no other options, I contacted apple support and they had no solution for me, so I'm stuck unable to use an app that I had previously purchased just because I am unable to update to the latest OS since my iMac is older and not compatible with any version higher than Catalina.

Fernandorenedo wrote:

Back when I purchased it, it was part of iLife package which also included garage band

I see. So you never actually downloaded iMovie separately. That could explain why in your case.

Not if you hadn't downloaded it previously.

FWIW, iMovie was/is free so you didn't actually purchase it. I did try to download it to an iMac running Catalina and it wouldn't download for me either, despite being in "Purchased".

Back when I purchased it, it was part of iLife package which also included garage band

Well, I CAN download it to a High Sierra VM so something odd is going on. You and I should be able to download iMovie 10.2.5 to Catalina but for some reason it's not working.