Css Megamenu does not appear in combination with my template

My preferred template is Joomspirit 121. css Megamenu does not appear in this template if the page is narrow. The left colum is empty. The creator of the template Joomspirit 121 does not help me.

My Test-Installation is:
URL: Test-Page

Hi U. Steimle.
1.I fixed it for you. Please check your site and feedback to me again,
I wrote some line code in to Custom CSS in advanced tab of Css3 mega menu module.
@media screen and (max-width: 768px){
body > .wrapper-website{
overflow:visible!important;
}
.js-megamenu-off-canvas{
left:-279px!important;
}
}
2. You can help me. write a review and vote 100point for each section for our product on JED:
extensions.joomla.org/extension/joomla-css3-mega-menu
Thank your so much for your review.

Hi Mrs. Tran,

sorry, but I can't see the result of your change. On small screen, the new left column is still very empty (???)
VG U. Steinke

Hi U.Steunke.
I'm sorry. Because you create 2 module megamenu. one for UK language and one for Deutsch language.
I add line code in UK language.
Now. I add for UK language and Deutsch language.
Please check it again.

Hi Mrs. Tran,

ok, yes, now I see the Menu, but the Sub-Menus don't appear:

VG U. STeinke

Hi U. STeinke
I'm sorry again.
I forget select enable jquery... in advanced of module for Deutsch language.
Please check it again. and
You can help me. write a review and vote 100point for each section for our product on JED:
extensions.joomla.org/extension/joomla-css3-mega-menu
Thank your so much for your review.