Unable to open 'Appium' on Mac OS version macOS Catalina 10.15.6

I’m trying install & open ‘Appium’ app (.dmg) 1.17.1 & 1.18.1 on mac machine, but getting below error: Appium can’t be opened because Apple cannot check it for malicious software.

In System preferences -> "Security & Privacy’ settings I have chosen option ‘Allow apps downloaded from App store & identified developers’ but still I’m getting same error.