I didn't understand the events

I do

curl -v -u asterisk:asterisk -X GET “http://my-ip:8088/ari/events

or

curl -v -u asterisk:asterisk -X GET “http://my-ip:8088/ari/events?app=myApp

where myApp is a websocket bound in asterisk (Creating Stasis app ‘myApp’)

then result is:

426 Upgrade Required

Upgrade Required

(null)


Asterisk Server

Why? Where do I mistake?
thanks