# Azure Functions (Isolated Worker) Upgrade Version 3 to 4


## Code first API to set connection string

Setting the connection string can now be done as part of calling `UseNServiceBus()`

Instead of

```csharp
functionsHostBuilder.UseNServiceBus(() => new ServiceBusTriggeredEndpointConfiguration(endpointName){
    ConnectionString = "CONNECTIONSTRING"
});
```

use:

```csharp
functionsHostBuilder.UseNServiceBus(endpointName, "CONNECTIONSTRING");
```