Unable to create new webapi project

I am creating my first ASP.NET Core Web API project using .NET Core, but when I create my project in PowerShell using command

dotnet new webapi -n FirstProject

The template "ASP.NET Core Web API" was created successfully.

Processing post-creation actions...Restoring D:\Applications Setup\FirstProject\FirstProject.csproj:  Determining projects to restore...D:\Applications Setup\FirstProject\FirstProject.csproj : error NU1101: Unable to find package Microsoft.AspNetCore.OpenApi. No packages exist with this id in source(s): C:\Program Files\dotnet\sdk\7.0.302\Sdks\Microsoft.NET.Sdk.Web\library-packs, Microsoft Visual Studio Offline PackagesD:\Applications Setup\FirstProject\FirstProject.csproj : error NU1101: Unable to find package Swashbuckle.AspNetCore. No packages exist with this id in source(s): C:\Program Files\dotnet\sdk\7.0.302\Sdks\Microsoft.NET.Sdk.Web\library-packs, Microsoft Visual Studio Offline Packages  Failed to restore D:\Applications Setup\FirstProject\FirstProject.csproj (in 125 ms).Restore failed.Post action failed.Manual instructions: Run 'dotnet restore'

I have also installed the latest version of .NET sdk. Why I am getting this error? Can someone help?

Thanks