Only the first page works after configuring Flask with uWSGI and nginx - what's causing the redirection 404s?

Question

Flask uWSGI nginx redirections problems error 404

I have configured the server like this https://www.digitalocean.com/community/tutorials/how-to-serve-flask-applications-with-uswgi-and-nginx-on-ubuntu-18-04

But there is only the first page who are working. Every redirections with flask are failing: 404 I don't understand because everything was working with the local Flask server before deployment.

This is an example of redirection :

@app.route("/settings", methods = ["POST"])
def settings():
  return render_template("parametres.html")