macOS blocks apps that are not from the App Store. This is expected — follow these steps the first time you open it.
Open the .dmg fileDouble-click the downloaded file, then drag the app icon into the Applications folder.
Try to open the app onceOpen Diwan Al Oud POS from Applications. A warning will appear saying Apple could not verify the app. Click Done.
Allow it in SettingsGo to System Settings → Privacy & Security, scroll down to the Security section, and find the line "Diwan Al Oud POS was blocked…". Click Open Anyway.
Enter your Mac passwordConfirm with your password or Touch ID, then click Open Anyway once more. The app starts.
DoneYou only need to do this once. From now on the app launches normally from Launchpad or Applications.
On recent versions of macOS, right-clicking the app and choosing Open no longer works. Use System Settings → Privacy & Security → Open Anyway as described above.
Enter Password
This download is protected. Please enter the access password provided to you.