使用css将Jsonify返回到html页面

I am currently working on a FLASK app that handles user logins. The idea behind it is that when a user enters his login credentials, the form would send his information to an API that will determine if the login is successful or otherwise. The API will send a message to display if it was a success or not. The API and template pages work fine and I am able to return the message using jsonify but I would like to return the jsonify data to a html page which has my css designs and extends my "base.html" Here's what I have so far:I am currently working on a FLASK app that hand