Can I change the SpaProxyLaunchCommand from program.cs in ASP .NET Core 6?

I created an ASP.NET Core 6.0 with Angular Ap in Visual Studio

In the .csproj file you can find the property:

<SpaProxyLaunchCommand>npm start</SpaProxyLaunchCommand>

I want to change it to programmatically in program.cs like:

var startupLanguage = "en-US";
SpaProxyLaunchCommand = $"npm run start-{startupLanguage}";

How can I do this?