I am switching from SQL Server to PostgreSQL, and have a webAPI that I have updated as follows:

In the appsettings.json file:

{
  "ConnectionStrings": {
    "postgres": "User ID=test;Password=testing;Server=localhost;Port=5432;Database=mpau;"
  },

  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

And in the Program.cs file:

using Microsoft.EntityFrameworkCore;
using Npgsql;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

//added
builder.Services.AddCors(options =>
{
    options.AddDefaultPolicy(
        policy =>
        {
            policy.AllowAnyOrigin();
            policy.AllowAnyMethod();
            policy.AllowAnyHeader();
        });
});

//added
builder.Services.AddDbContext<mpauDbContext>(options =>
{
    builder.Configuration.GetConnectionString("postgres");
    options.UseNpgsql("postgres");

});


builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseAuthorization();

app.MapControllers();

app.Run();

I was able to create the data migrations, however when I try update-database, I get an error stating:

"Format of the initialization string does not conform to specification at index 0"

Most search results state that it is likely caused by an error in the connection string, but I have tried multiple changes, and I followed a tutorial where the string used was almost identical (with the exception of username and password, and I will be trying Kerberos authentication later to remove this from the connection string).

Any help in resolving this error would be greatly appreciated.