First time with easy timer and shortcodes

Hi
I’m trying to insert easy timer in my sidebar, but i think the shortcode doesn’t work.
I think I have to hadsomething in ‘function.php’ but what ?
thanks for your help
Bruno

my website : http://www.dispapacestlointahiti.fr

http://ww.wp.xz.cn/extend/plugins/easy-timer/