Try to use layer but get error

[rkstyle]

Hello masters!
I try to use my wt layer but i found error in my dev console. 

<!-- 
gamification_bt.js:143 Could not find proper place to add the gamification notification center. x_x
gamificationInsertOnBackOfficeDOM @ gamification_bt.js:143
gamificationTasks @ gamification_bt.js:10
(anonymous) @ gamification_bt.js:2
j @ jquery-1.11.0.min.js:2
fireWith @ jquery-1.11.0.min.js:2
ready @ jquery-1.11.0.min.js:2
K @ jquery-1.11.0.min.js:2
gamification_bt.js:13 Uncaught ReferenceError: admin_gamification_ajax_url is not defined
    at gamificationTasks (gamification_bt.js:13)
    at HTMLDocument.<anonymous> (gamification_bt.js:2)
    at j (jquery-1.11.0.min.js:2)
    at Object.fireWith [as resolveWith] (jquery-1.11.0.min.js:2)
    at Function.ready (jquery-1.11.0.min.js:2)
    at HTMLDocument.K (jquery-1.11.0.min.js:2)

-->

Can i fix this error ?