Flask-Restplus middleware

Question

I have made an api with restplus

from flask_restplus import Namespace, Resource, fields
from flask import request
from flask_restplus import abort

api = Namespace('myproject', description='My API')

@api.route('/run')
class MyProject(Resource):
    @api.doc(params={'name':'name'})
    def post(self):
        #doing stuff
        return {'status':'started'}

The point of this route is to run another function and return {'status':'started'} immediatly without waiting for the function to end.

I've found this https://stackoverflow.com/a/51013358/1540114 but I have trouble using it in my project from what I understood the AfterResponse is a middleware that I can apply to my route

I tried using it like this

....
api = Namespace('myproject', description='My API')
AfterResponse(api)

@api.after_response
def say_hi():
    print("hi")

@api.route('/run')
class MyProject(Resource):
....

but it gave me an error stating that api doesn't have a wsgi_app property