Property for data annotations missing when generating client using NSwag

[tilenzalar]

I have a project (C# API and Blazor WebAssembly client side). I have this data annotation on one of my property.

[Required(ErrorMessage = "My custom error message")]
public string Client { get; set; }

I'm using NSwag to generate my client side. NSwag generates this:

[Newtonsoft.Json.JsonProperty("client", Required = Newtonsoft.Json.Required.Always)]
[System.ComponentModel.DataAnnotations.Required(AllowEmptyStrings = true)]
public string Client { get; set; }

So property "ErrorMessage" was not generated. It should generate:

[System.ComponentModel.DataAnnotations.Required(AllowEmptyStrings = true, ErrorMessage = "My custom error message")]

I can add this manually, but I would like that NSwag generates this. Is this not possible or am I missing something?

*I've found this similar topic #2297 (comment) but I can't help myself with it.

[RicoSuter]

Is this not possible or am I missing something?

Open API does not have a way to describe this - ie its not possible ATM.
However with custom properties and custom templates it would be possible...