Why is it impossible to get my favicon in flask_restful and apispec swagger ui?

Question

I'm trying to build a restful api in python using flask and flask_restful also I use flask_apispec to build a swagger documentation. I want to use my favicon that is in my static/ folder but when I run my app I get this error message :

RuntimeError: Working outside of application context. This typically means that you attempted to use functionality that needed the current application. To solve this, set up an application context with app.app_context(). See the documentation for more information.

can you help me understand ? here is my code:

import sys
from flask import Flask, url_for
from flask_restful import Resource, Api
from apispec import APISpec
from marshmallow import Schema, fields
from apispec.ext.marshmallow import MarshmallowPlugin
from flask_apispec.extension import FlaskApiSpec
from flask_apispec.views import MethodResource
from flask_apispec import marshal_with, doc, use_kwargs

app = Flask(__name__)
app.config.update({
    'APISPEC_SPEC': APISpec(
        title='Health API',
        version='v1',
        plugins=[MarshmallowPlugin()],
        openapi_version='2.0.0',
        info={
            'description': 'This is the API for the Health project',
            'x-logo': {
                'url': url_for('static', filename='favicon.ico')
            }
        }
    ),
    'APISPEC_SWAGGER_URL': '/doc/',
    'APISPEC_SWAGGER_UI_URL': '/doc-ui/'
})
app.add_url_rule('/favicon.ico', redirect_to=url_for('static', filename='favicon.ico'))

api = Api(app)
docs = FlaskApiSpec(app)


class HelloWorldResponseSchema(Schema):
    message = fields.String()


class HelloWorld(MethodResource, Resource):
    @doc(description='Hello World!')
    @marshal_with(HelloWorldResponseSchema)
    def get(self):
        return dict(message='Hello World! get')

    @marshal_with(HelloWorldResponseSchema)
    def post(self):
        return dict(message='Hello World! post')


api.add_resource(HelloWorld, '/')

docs.register(HelloWorld)

if __name__ == '__main__':
    ARGDEBUG = len(sys.argv) > 1 and sys.argv[1] in ('-d', '--debug')
    app.run(DEBUG=ARGDEBUG)