Blazor----------------------
<button onclick="Handle()">Click</button>

@using Microsoft.JSInterop
@inject IJSRuntime JS

@code {
    protected async Task HandleClick()
    {
        await JS.InvokeVoidAsync("Handle");
    }
}

Javascript----------------------(inside wwwroot)
function Handle() {
    console.log("Navbar toggle!");
}

call in index.html--------------------
<script src="script.js"></script>