CS0117 - 'HttpClient' does not contain a definition for 'GetFromJsonAsync'

I'm following the Microsoft tutorial on Blazor. I'm getting the 'HttpClient doesn't contain a definition for 'GetFromJsonAsync' error when trying to use this extension method in the Index.razor page. System.Net.Http.Json (v. 6.0.0) is installed.

This is what my Index.razor file looks like:

@page "/"@using System.Net.Http.Json<div class="main"><h1>Blazing Pizzas</h1><ul class="pizza-cards">        @if (specials != null)        {            @foreach (var special in specials)            {<li style="background-image: url('@special.ImageUrl')"><div class="pizza-info"><span class="title">@special.Name</span>                        @special.Description<span class="price">@special.GetFormattedBasePrice()</span></div></li>            }        }</ul></div>@code{    // List of special offers    List<PizzaSpecial> specials = new();    protected override async Task OnInitializedAsync()    {        specials = await HttpClient.GetFromJsonAsync<List<PizzaSpecial>>(NavigationManager.BaseUri +"specials");    }}

I've tried installing a newer version of System.Net.Http.Json but the error persisted.