Hey @somvannda,
I haven’t used any particular package so far (I made my own custom implementation), so I can’t help you much here, sorry.
My wild guess would be that you copy the code from the AdminLTE demo template and put it in your Blaze template like this for example:
<template name="mainMenu">
{{#AdminLTE skin="green"}}
<!-- paste HTML code you copied from the AdminLTE template>
{{/AdminLTE}}
</template>