code: def handle_profile_form(form):
      
      form.process(formdata=request.form)
  
      if form.validate_on_submit():
          email_changed = False
          with db.session.begin_nested():
              # Update profile.
              current_userprofile.username = form.username.data
              current_userprofile.full_name = form.full_name.data
              db.session.add(current_userprofile)
  
              # Update email
              if current_app.config['USERPROFILES_EMAIL_ENABLED'] and \
                 form.email.data != current_user.email:
                  current_user.email = form.email.data
                  current_user.confirmed_at = None
                  db.session.add(current_user)
                  email_changed = True
          db.session.commit()
  
          if email_changed:
              send_confirmation_instructions(current_user)
              # NOTE: Flash message after successful update of profile.
              flash(_('Profile was updated. We have sent a verification '
                      'email to %(email)s. Please check it.',
                      email=current_user.email),
                    category='success')
          else:
              # NOTE: Flash message after successful update of profile.
              flash(_('Profile was updated.'), category='success')
docs: Handle profile update form.