Published the app using appwrite site, authorization fails Unexpected token '<', "<!doctype

I have a very typical issue "it works on my machine" .I am building an app using Auth, Database and Storage modules. The authentication works perfectly in my local machine, however I published this using Appwrite site and auth fails (login / sign-up) with error saying

"Unexpected token '<', "<!doctype "... is not valid JSON"

What am I doing wrong?
https://petsagram.appwrite.network/

that seems like u got an html error? can u check what that says?

Thanks @Chirag Aggarwal it's solved. It was expecting JSON response while the function was returning HTML