Cannot get a circle on the Leaflet Map when user clicks on the button - Blazor

Question

I'm trying to get a circle of certain radius when the user click on the button. My application is in Blazor. I've started with initialise function which works well. However, the GetCircle() function doesn't work and it gives me an exception error 'map.addLayer is not a function' I.

When I also tried to declare the map and circle variable to the top of the code, the error turns to 'Cannot read properties of undefined (reading '_leaflet_id''

Here is my js:

window.myMap = {
    initialise : function(){
var map = L.map('map').setView([51.75164151931502, -1.2382256195107832], 15);

L.tileLayer('https://api.mapbox.com/styles/v1/{id}/tiles/{z}/{x}/{y}?access_token={accessToken}', {
    attribution: 'Map data &copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
    maxZoom: 18,
    id: 'mapbox/streets-v11',
    tileSize: 512,
    zoomOffset: -1,
    accessToken: '----'

}).addTo(map);

  var marker = L.marker([51.75262676993951, -1.2533975397416488]).addTo(map);


  map.on('click',function(e) {
    if (marker !== null ) {
        map.removeLayer(marker);
    }
   
    marker = new L.Marker(e.latlng);
    map.addLayer(marker);
    
});
},
GetCircle: function()
{
  //here is the issue

    var circle = L.circle([51.75262676993951,-1.2533975397416488],{radius:300});
   
    map.addLayer(circle);

}


};

this is my Blazor Component:

@page "/testt"
@inject IJSRuntime JSRuntime
@using Microsoft.JSInterop



<style>
    #map {
    height: 600px;
}
       
</style>
<br>
 <div class="col-9" id="map"  ></div>
<button @onclick="GetCircle">
Get Area
</button>

 @code{

     protected override async Task OnAfterRenderAsync(bool firstRender)
{

if (firstRender)
    {
        await JSRuntime.InvokeVoidAsync("myMap.initialise");

        StateHasChanged();
    }
}
      public async Task GetCircle()

    {
        await JSRuntime.InvokeVoidAsync("myMap.GetCircle");
        
    }
}
 

I'm getting 'map.addLayer is not a function' I've tried to put 'addTo(map)' instead of addLayer and the same error came out.

Any hint?