Is it possible to Update the Service Definition from the json?

[Iron_Mark]

Hi,

I had to modify an old survey123 form by deleting multiple questions and republish it with additional new ones.

Now I want to change the order of the various fields. I know how to change the pop up order, and I did it, but when I download the csv it gives me the old order.

So I went to the "Arcgis REST Services Directory" page in Admin mode and clicked on Update definition. Then I changed the order of the fields in the json and clicked "Update service Definition", but I ger errors (see attached), or eventually it says "Invalid Token". 

So the questions are:

-Is i tpossible to update the service definition this way?

-What is the correct way of doing it? Can I get a bit of workflow please?

Thank in advance