Installation

Allow APK installation on Android

Give installation permission to the app that is opening your trusted APK.

Open Settings → Apps → Special App Access → Install Unknown Apps. Some devices use Security & Restrictions or another similar label.
Select Downloader, your browser, or the file manager you are using to open the APK.
Enable Allow from this source for that app, then return to the downloaded APK and choose Install.
After installation, you can turn that permission off again.

Still need a hand?

Send Davie your device model, the exact error and the steps you have tried.