How do you place waypoints on your map in MInecraft PE

On Minecraft Java Edition, if you right-click a banner with your map, the banner will show up on the map, but because you're on Minecraft Bedrock Edition, you'll have to use a slightly more difficult way. In my past survival worlds, I have taken concrete of different colours, and laid them out in a large square, so that it shows up on the map. If you don't want a large area of concrete right next to your locations, you can just lock your map by putting it in a cartography table with a glass pane, and destroy the concrete afterwards. The square will stay on the map.

Note: You can use any block you want, I just like using concrete blocks.