Leaflet markere is not accept Draggable feature

ionic ionic-v3
#1

In this code {draggable:'true'}feature is not accepted and makes error:

import { Component, OnInit } from '@angular/core';
import { NavController } from 'ionic-angular';

import * as Leaflet from 'leaflet';

@Component({
  selector: 'page-street',
  templateUrl: 'street.html'
})
export class StreetPage {
 private latLng: any;
  private marker: any;
  private map: any;  
  constructor(public navCtrl: NavController) {

  }
  ngOnInit(): void {
    this.drawMap();
  }
  drawMap(): void {
    let map = Leaflet.map('map');
    Leaflet.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
      maxZoom: 15
    }).addTo(map);

    map.locate({ setView: true});
    function onLocationFound(e) {      
      var radius = e.accuracy / 3;     
      Leaflet.marker(e.latlng, {draggable:'true'}).addTo(map);
      Leaflet.circle(e.latlng, radius).addTo(map);
    }
    map.on('locationfound', onLocationFound);
    //alert on location error
    function onLocationError(e) {
      alert(e.message);
    }
    map.on('locationerror', onLocationError);
  }   
}

any Idea to solve it?

#2

Update:

error for {draggable:'true'} :

Typescript Error Argument of type ‘{ draggable: string; }’ is not assignable to parameter of type ‘MarkerOptions’. Types of property ‘draggable’ are incompatible. Type ‘string’ is not assignable to type 'boolean

error for{draggable: true} :

Typescript Error Argument of type ‘{ draggable: true; }’ is not assignable to parameter of type ‘MarkerOptions’. Property ‘options’ is missing in type '{ draggable: true

#3

I find that, may I have to use Leaflet.marker(e.latlng, {'draggable':true} ).addTo(map); , now marker is draggable but the circle is not dragging with maker(it is not binded with marker) another question is how to read dragged marker position. in qoogle there was a ‘draggend’ event listener.