how to use other language option in localizer

Hi,

how to use other language option in localizer ? I need to use two language same time. other language option is changeable. 

namespace MIS.WebUI.Controllers
{

    public class HomeController : Controller
    {
        public readonly IStringLocalizer<SharedResource> Localizer;

        public HomeController(IStringLocalizer<SharedResource> _localizer)
        {
            this.Localizer = _localizer;
        }
        public IActionResult Index()
        {
            var title = Localizer["ModalMessageTitle"] + " / " + OTHER_LANGUAGE("en-GB")["ModalMessageTitle"] ;                
        }

    }
}