Is it possible to load a server side Blazor pages HTML before the code is executed?

Issac pointed to the solution in their comment:

Try to use OnAfterRenderAsync instead

I just write the code:

@code
{

    protected bool Rendered = false;

    protected async override Task OnAfterRenderAsync()
    {
        if (!Rendered) 
        {
            Rendered = true;
            await OnAfterFirstRenderAsync();
        }            
    }
    protected async Task OnAfterFirstRenderAsync()
    {
        data = await TaskService.GetDataAsync();
    }
}