Resolved: Swagger/OpenAPI static file not appearing

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddRazorPages();
builder.Services.AddControllersWithViews();

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    app.UseHsts();

    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseAuthorization();

app.MapDefaultControllerRoute();
app.MapRazorPages();

app.Run();

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.3.1" />
    <PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="6.3.1" />
    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="6.3.1" />
    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="6.3.1" />
  </ItemGroup>
  <Target Name="PostBuild" AfterTargets="PostBuildEvent">
    <Exec Command="dotnet tool restore" />
    <Exec Command="dotnet new tool-manifest --force" />
    <Exec Command="dotnet tool install --local Swashbuckle.AspNetCore.Cli"/>
    <Exec Command="dotnet swagger tofile --output swagger.json $(OutputPath)\$(AssemblyName).dll v1 " />
</Target>
</Project>