Add Value to Turn Tracker from API

My token is selected and a macro calls an API. The API returns html-formatted content to the R20 Chat window.:

on("chat:message", function (msg) {        
     ... a lot of stuff happens...        
     sendChat("player|" + msg.playerid, "/direct " + strOutput + NetResults());
}

Everything works.

Now, I want to send additional information to the turn tracker via the same API. For example:

sendChat("player|" + msg.playerid, "/roll 5 &{tracker}");

This should add a turn tracker entry for the selected token with a value of '5'. It doesn't - it just displays the number '5' in the Chat output. (This works fine when typed directly into Chat...)

Thoughts?