How to use tilesLoaded in angular 8?

Add the tilesLoaded event to your agm-map as follows:

<agm-map  
  [latitude]=51.673858
  [longitude]=7.815982
  [zoom]=8
  (tilesLoaded)="handleOnTilesLoaded()">
</agm-map>

Then add your own behavior within that function, e.g.:

handleOnTilesLoaded(){
    console.log("Tiles have loaded.");
}

Hope this helps you!