njQuery is not defined

Hi,

for my website there is an issue in console ‘ReferenceError: njQuery is not defined’. This is caused by a script in html:

njQuery(document).ready(function () {
        njQuery('#nextend-smart-slider-4').smartslider({"translate3d":1,"playfirstlayer":0,"mainafterout":0,"inaftermain":1,"fadeonscroll":0,"autoplay":1,"autoplayConfig":{"duration":10000,"counter":0,"autoplayToSlide":0,"stopautoplay":{"click":1,"mouseenter":1,"slideplaying":1},"resumeautoplay":{"mouseleave":0,"slideplayed":1,"slidechanged":0}},"responsive":{"downscale":1,"upscale":0,"maxwidth":3000,"basedon":"combined","screenwidth":{"tablet":1070,"phone":640},"ratios":[1,1,0.7,0.5]},"controls":{"scroll":0,"touch":"horizontal","keyboard":0},"blockrightclick":0,"lazyload":1,"lazyloadneighbor":0,"randomize":0,"type":"ssSimpleSlider","animation":["horizontal"],"animationSettings":{"duration":1100,"delay":0,"easing":"easeInOutCubic","parallax":1},"flux":[1,["bars"]],"touchanimation":"0"});
    });

.

How may I resolve this problem?
Thank you!