How can I put the output of spctl command into a notification dialog using Automator?

I would like to output the result of

--assess --verbose path/to/app.app

in a notification dialog using Automator. However, it doesn't work. I assume it's because the command returns a multi-line output, such as

/Applications/Test.app: accepted

=Notarized Developer ID

I tried passing the output of the shell script to a Set Value of Variable action and then putting the variable in a Display Notification action. I tried using a Ask for Confirmation action instead. Since it didn't work, I tried passing the output of the command to a New TextEdit Document action, but the new document ended up blank. I tried appending

| tr '\n' ' '

to replace the new line character with a space but that didn't work. I would appreciate any help. Thanks.