Add content to text frame in Indesign

addContentTextFrame.jsx

#target indesign
app.documents.add();
app.documents[0].save();
app.documents[0].pages[0].textFrames.add({geometricBounds:[40,40,180,180]});
var myFrame = app.documents[0].pages[0].textFrames[0];
myFrame.contents = "Hello world";