profile picture won't upload in python/flask

I am new here and a beginner so i would be grateful for your help.I am trying to do Blog app in Flask. I got stuck on uploading profile picture. Default picture is working fine but when i try to upload new image it just won't work. It doesn't show any error. It seems to me that maybe there is problem with storing files but i couldn't figure out what is the problem. When I try to upload an image, the page just refreshes and the default image remains. Nothing is also saved in the profile_pictures folder. Here is my layout:

/Users/korisnik/PycharmProjects/Blog
├── project
├── ├──core 
|   ├──posts
|   ├──static
|   |   ├──profile_pictures
|   |       ├──default_profile_picture.jpg
|   ├──templates
|   ├──users
|   |   ├──__init__.py
|   |   ├──forms.py
|   |   ├──picture_handler.py
|   |   ├──views.py
|   ├──__init__.py
|   ├──models.py
├──app.py

Here is my code:

picture_handler.py

def add_profile_picture(pic_upload, username):
    filename = pic_upload.filename
    extension_type = filename.split(".")[-1]
    storage = str(username) + "." + extension_type

    filepath = os.path.join(current_app.rooth_path, "static/profile_pictures", storage)
    picture_size = (100, 100)
    pic = Image.open(pic_upload)
    pic.thumbnail(picture_size)
    pic.save(filepath)

    return storage

users.views.py

@users.route("/profile", methods=["GET", "POST"])
@login_required
def profile():
    form = ProfileForm()
    if form.validate_on_submit():
        if form.picture.data:
            username = current_user.username
            pic = add_profile_picture(form.picture.data, username)
            current_user.profile_image = pic

        current_user.username = form.username.data
        db.session.commit()
        return redirect(url_for("users.profile"))

    elif request.method == "GET":
        form.username.data = current_user.username

    profile_image = url_for("static", filename="profile_pictures/" + current_user.profile_image)
    return render_template("profile.html", profile_image=profile_image, form=form)

profile.html

{% extends "base.html"%}
{% block content %}

<div class="jumbotron">
    <div align="center">
        <h1>Welcome {{current_user.username}}</h1>
        <img src="{{url_for('static', filename='profile_pictures/' + current_user.profile_image)}}" align="center">
    </div>
</div>


<div class="container">
    <form method="POST" action="" enctype="multipart/form-data">
        {{form.hidden_tag()}}

        <div class="form-group">
            {{form.username.label(class="form-group")}}{{form.username(class="form-control")}}<br>
        </div>

        <div class="form-group">
            {{form.picture.label(class="form-group")}}{{form.picture(class="form-control")}}<br>
        </div>

        <div class="form-group">
            {{form.submit(class="btn btn-primary")}}
        </div>

    </form>
</div>
{% endblock %}