Flask-mail how to embed image in html body

Question

I'm using Flask-Mail to send emails with an html body. I would like to have a logo on top of the body but all I get is a question mark.

in the @app.route I tried this

//some code...
app.open_resource("LogoFatWatch2.0_50.png") as fp:  
        img=("LogoFatWatch2.0_50.png","image/png",fp.read()) 
    msg.html = render_template('passwordReset.html', token=fullToken, img=img, username=username.usr_name)

the html file

<img style="padding-bottom: 50px; width: 50px;" src="{{img}}">

I also tried with the logo full path and even with the whole url but was unsuccessful. And {{url_for}} also doesn't work

If send it as an attachment it is visible but of course at the bottom of the email.