btcpayserver/BTCPayServer/Extensions/EnumExtensions.cs

using System;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Reflection;

namespace BTCPayServer
{
    public static class EnumExtensions
    {
        public static string DisplayName(this Type enumType, string input) => 
            enumType.GetMember(input).First().GetCustomAttribute<DisplayAttribute>()?.Name ?? input;
    }
}