Handling multiple async calls inside for loop

I have a javascript for loop where I call a function for each lat-lng bound, inside this function I execute THREE async calls to google maps Places API, after all three calls execute I color the bounds green.

Issue is my for loop executes in a sync way and all bounds are colored green in a single tick instead of aiting for all three async calls to resume.

How can I do it so the for loop waits for the async calls to execute before going to the next iteration?

My code:

async startScrapingGridLoop()
    {
        const self = this;

        for (var i = 0; i < self.zoneBoundaries.length; i++)
        {
            //Multiple async calls
            await self.scrapeCellWithPlaces(self.zoneBoundaries[i]);
            //After all three async calls end I want to color the bound green
            let currentPolygon = self.polygonsArray[i];
            currentPolygon.setOptions({fillColor: 'green', fillOpacity:0.6});

        }
    },

async scrapeCellWithPlaces(zoneBoundaries)
    {
        const self = this;
        var request = {};
        var bounds = new google.maps.LatLngBounds(new google.maps.LatLng({ lat:zoneBoundaries.sw.lat(), lng:zoneBoundaries.sw.lng() }), new google.maps.LatLng({ lat:zoneBoundaries.ne.lat(), lng:zoneBoundaries.ne.lng() }));


        for (var i = 0; i < self.types.length; i++)
        {
                
                
            request = { bounds: bounds, type: self.types[i] };
                
            self.placesService.nearbySearch(request, self.scrapeCellWithPlacesCallback);
            console.log('Scraping bounds for '+self.types[i]);
        }

    },

scrapeCellWithPlacesCallback(results, status, pagination)
    {
        const self = this;
         
        if (status == google.maps.places.PlacesServiceStatus.OK)
        {      
            for (var i = 0; i < results.length; i++)
            {
                self.results.push(results[i]);
            } 

            //self.setPlacesMarker(self.results);
            //self.fitPlacesBounds(self.results);
            
            if (pagination.hasNextPage)
            {
                console.log('fetching next set of sets');
                sleep:3;
                pagination.nextPage();

                for (var i = 0; i < results.length; i++)
                {
                    self.results.push(result[i]);
                } 
            }
        }
        console.log(self.results);
    },