Okay....so I took a look at it and compared how it was coded vs how your JSON script was coded. Since the two was kinda unclear to tell exactly what the brackets were. I think I saw some red flags of yours that I notice looking at the tutorial scrpt...
I put the number so you can tell where I think your mistakes were at. At the beginning of 1. is the bracket green like in the tutorial JSON you copied from?
On 2, I not sure if it makes a difference but the brackets seem a little too spaced apart and the "]" above the circle of 2 of you Coding, should be over a bit like it is in the original JSON script.
and for 3, I notice after it says "Dialogs": { in the orginal JSON script, your is scripted like this "Dialogs:{[ ......should this "[" be below that, like it is in the Original JSON script?