Sending popup message to other Mac

Given two Macs within the same wifi network. I would like to send a popup message from one to other (as I would do it in Windos environment via NET SEND).

As advised in this forum, in reply #2 of this discussion, I set remote apple events enabled in the target machine:

Then I created and run the following applescript on the other machine:

IP address is correct for sure. When I started the script, it prompted for administrator credentials of the target machine which I provided.

Then the following error message appeared, in spite of having remote apple events enabled on the target machine:

What else must be set in oder to get it work?