A basic implementation of using the Google Maps JS API with a DrawingManager in React with TypeScript without relying on one of the amazing (but poorly maintained) libraries.

Map.tsx

import { useEffect, useState } from "react";

interface IMapProps {
  // so that the parent can get a reference to the google maps instance
  onMapLoaded?: (next: google.maps.Map) => void;
  // so that the parent can get a reference to 
  onDrawingManagerLoaded?: (next: google.maps.drawing.DrawingManager) => void;
  className?: string;
}

const Map = (props: IMapProps) => {
  const [map, setMap] = useState<google.maps.Map>();
  const [
    drawingManager,
    setDrawingManager,
  ] = useState<google.maps.drawing.DrawingManager>();

  // gets called after the Google Maps JS API is downloaded
  const onScriptLoaded = () => {
    setMap(
      new window.google.maps.Map(document.getElementById("map")!!, {
        center: { lat: -19.747778, lng: -47.931944 },
        zoom: 12,
        disableDefaultUI: true,
        mapTypeId: "hybrid",
      })
    );
  };

  // inform the parent when the map gets loaded/reloaded
  useEffect(() => props.onMapLoaded && map && props.onMapLoaded(map), [
    map,
    props.onMapLoaded,
  ]);
    
  // inform the parent when the drawing manager gets loaded/reloaded
  useEffect(
    () =>
      props.onDrawingManagerLoaded &&
      drawingManager &&
      props.onDrawingManagerLoaded(drawingManager),
    [drawingManager, props.onDrawingManagerLoaded]
  );

  // watch for changes to the map instance and create a drawing manager
  useEffect(() => {
    if (map)
      setDrawingManager(
        new google.maps.drawing.DrawingManager({
          drawingMode: google.maps.drawing.OverlayType.POLYGON,
          drawingControl: false,
          map: map,
        })
      );
  }, [map]);

  // watch for window changes and add the script tag to the head
  useEffect(() => {
    if (!window.google) {
      var s = document.createElement("script");
      s.type = "text/javascript";
      s.src = `https://maps.google.com/maps/api/js?key=<YOUR_API_KEY>&libraries=drawing`;
      var x = document.getElementsByTagName("script")[0];
      x.parentNode!!.insertBefore(s, x);
      // Below is important.
      //We cannot access google.maps until it's finished loading
      s.addEventListener("load", onScriptLoaded);
    } else {
      onScriptLoaded();
    }
  }, []);
    
  return <div className={props.className} id="map" style={{height: "500px", width: "500px"}} />;
};

export default Map;

package.json

{
  "name": "agri",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.11.4",
    "@testing-library/react": "^11.1.0",
    "@testing-library/user-event": "^12.1.10",
    "@types/jest": "^26.0.15",
    "@types/node": "^12.0.0",
    "@types/react": "^17.0.0",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "react-router": "^5.2.0",
    "react-router-dom": "^5.2.0",
    "react-scripts": "4.0.3",
    "typescript": "^4.1.2",
    "web-vitals": "^1.0.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "devDependencies": {
    "@types/google.maps": "^3.44.2"
  }
}