macOS displays a dialog containing this error and the options "Move to Bin" and "Cancel" when launching unsigned applications for the first time:

"* cannot be opened because the developer cannot be verified"

To allow list via the CLI:

xattr -r -d com.apple.quarantine "$(which session-manager-plugin)"

Else, locate the app or binary in Finder:

open -R "$(which session-manager-plugin)"

Then right-click it and select Open.