[Question] How to extend a builtin module

Hey Victor! Extending UI pages can be done with page extenders. I answered this same question pretty recently and wrote up this sample code:

[assembly: PageExtender(typeof(EventLogExtender))]
namespace MySite
{
    public class EventLogExtender(IHttpContextAccessor httpContextAccessor) : PageExtender<EventLogList>
    {
        public override Task ConfigurePage()
        {
            Page.PageConfiguration.HeaderActions.AddCommand("Clear log", nameof(Clear));

            return base.ConfigurePage();
        }

        [PageCommand]
        public async Task<ICommandResponse> Clear()
        {
            var authenticatedUserAccessor = httpContextAccessor.HttpContext.RequestServices.GetRequiredService<IAuthenticatedUserAccessor>();
            var user = await authenticatedUserAccessor.Get();
            EventLogHelper.ClearEventLog(user.UserID, user.UserName, httpContextAccessor.HttpContext.Connection.RemoteIpAddress.ToString());

            return Response().UseCommand("LoadData").AddSuccessMessage("Event log cleared");
        }
    }
}

This also logs a "Log cleared" event after the button click (like we did in K13) so you can audit who is clearing the Event log. I find that I can usually guess the class that I need to reference in PageExtender<T> but if you're not sure, you can find the backend template in System > UI Tree: