I suspect it is because the app is 32 bit? Can anyone help?

Yes you can't run 32bit apps. Apple dropped this feature in 2018 with the release of 10.15 Catalina so 5 years ago. What year is your mac? Is it intel? If so It will run windows out of the box. I'm unsure what the M1 and M2 chips can do it's beyond my territory. If you have a Mojave capable machine try partition the hardrive and install it for 32 bit. Or try an emulator. I'm mot entirely sure how people worked around 32bit apps in 2018 but there are ways. I'm still on mountain lion haha.

Join the Low end macbook Facebook page and they should be able to help you there good luck.