Since official support has ended, you may need to use manual installation workarounds: :
Emma started her search by visiting the official Umax website, but unfortunately, the website didn't have a clear download section for scanner drivers. The links seemed to be broken, and the search bar yielded no results. Frustrated but not defeated, Emma turned to online forums and communities for help. She stumbled upon a post from a fellow designer who had successfully installed a driver for the same scanner model. Umax Astra 5800 Scanner Driver Free Download
Drop files