How can I implement a landing page for my non-custom domain using a HTTPS certificate provided by pythonanywhere.com?

@app.route("/",  methods=['GET', 'POST'])
def index():
    if current_user.is_authenticated:

        greetings = f'Hello {current_user.email} !'

    else:
        greetings = 'Hello, please login'

    return render_template("landing.html", greetings=greetings)

@app.route("/login", methods=['GET', 'POST'])
@auth_required()
def home():
    if current_user.is_authenticated:

        greetings = f'Hello {current_user.email} !'
        return render_template("home.html", greetings=greetings)

    else:
        return redirect("/", code=302)


@app.route('/logout', methods=['GET', 'POST'])
@auth_required()
def logout():
    logout_user()

    return redirect("/", code=302)