How to run flask with ssh tunnel on localhost.run?

I want to connect my localhost from flask to a public address.

This is my simple flask app (also a simple index.html with 2 buttons):

from flask import Flask, render_template, request 
app = Flask(__name__)

@app.route("/", methods=['GET', 'POST'])
def index():
    if request.method == 'POST':
        if request.form.get('action1') == 'VALUE1':
            print('Value1')
        elif request.form.get('action2') == 'VALUE2':
            print('Value2')
    return render_template("index.html")

if __name__ == '__main__':
    app.run()

I managed to established a connection with MAMP and localhost.run, but when I try to change the port from flask it gives me an error on the final result (not a crash, just "this page isn't working).

I need this because I want to run some codes from my pc using a webpage.