why i cant download my apps education

Hello hye apple, i want to ask , on 2020 i’ve done download my uitm education apps, the uitm education apps is privacy, and if someone want to download the apps need tu check on device management on the setting ios... then i uninstalled the app on my phone , but now i really need the apps again to check my result exam, i’ve try to download the apps by website cause there not shown on apps store, but still cant download.. in the setting>general still not show the device management, so what should i do ya 😭