title: How to let the user to build a polygon on the open street map?
body: <p>UPD: Done. Look at this beautiful polygon. <a href="https://i.stack.imgur.com/dnpyX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dnpyX.png" alt="enter image description here" /></a></p>
  <p>UPD: In Flutter / openstreetmap, I want to let users draw a polygon by tapping a map and/or clicking a button. The polygon should be not filled. I need a very simple example just to get an idea of how it works.</p>
  <p>The final task is:</p>
  <p>I am making a flutter application that should give the user the ability to get information about markers located within a certain area on the map. I use osm. By pressing the button, the user initiates the construction of an arbitrary polygon, each corner of which is formed at the place of the next pressing of the button. When the construction of the polygon is completed, the objects inside the polygon are shown, the rest are hidden or not built. After that, the cycle ends by clearing the map.</p>
  <p>I haven't found any solution for osm. I would appreciate any help. I don't have any code yet)</p>