My attempts to run a NET call from JS ended in failure.
Tried including examples from Microsoft.
But adding to the page

@rendermode InteractiveServer

So that the button would work. Causes an error.

Here is the code that worked in .NET 7

async Task Up()
{
    await JS.InvokeVoidAsync("Crop.responses", DotNetObjectReference.Create(this), Id);
   crop2View = "opcity-0";
}

[JSInvokable]
public async void ResponseMethod(string data)
{
    model.Base64 = data;
    await UploadServer();
    StateHasChanged();
}

JS code

var base64data;

window.Crop = {        
    responses: function (component, id) {
        resize.result('blob').then(function (blob) {
            var reader = new FileReader();
            reader.readAsDataURL(blob);
            reader.onloadend = async function () {
                base64data = reader.result;
                var i = document.getElementById('result-' + id);
                var img = document.createElement('img');
                img.src = base64data;
                i.appendChild(img);
                return component.invokeMethodAsync('ResponseMethod', base64data);
            }
        });

    }
};

How to call ResponseMethod from JS