Flask Send Data to server – Blancer.com Tutorials and projects

I am new to flask and I start to learn post and get requests. I do them with a form.
FLASK

from flask import Flask,render_template,request
app = Flask(__name__)
@app.route("/a",methods=['POST','GET'])
def home():
    if request.method == 'POST':
        a = request.form['name']
        print(a)
    return render_template('index.html',b=a)
if __name__ == '__main__':
    app.run(debug=True)

HTML

<!DOCTYPE html>
<html>
    <body>
        <form action="" method='post'>
            <input type='text' name='name'>
            <button>OK</button>
        </form>
        <p>{{b}}</p>
    </body>
</html>

How can I send data like this but without a form?

When I run it I get "POST /a HTTP/1.1" 200 -

Thanks.