按钮未添加到Javascript滑块

我正在工作&我想在网站主页英雄部分的滑块中显示的每个图像下方添加一个文件下载按钮

由于某种原因，按钮未添加，滑块损坏。我没有建立这个网站，只是收到了这个任务。这就是为什么我不能理解用于slider的JS&这就是为什么被卡住了

当前正在尝试的代码：

<div  id="slider"  class="nivoSlider templatemo_slider">
<a href="javascript:ver_contenido(2);">
    <img src="images/slider/fslider1.jpg" alt="slide 1"/>
    <button type="submit" onclick="window.location('pdf\Catalog 2020-DEC PMEC-Final_compressed.pdf')">Download!</button>
    <a href="pdf\Catalog 2020-DEC PMEC-Final_compressed.pdf" download="Catalog 2020-DEC PMEC">Download</a>
</a>
<a href="javascript:ver_contenido(5);"><img src="images/slider/fslider2_en.jpg" alt="slide 2"/></a>
<a href="javascript:ver_contenido(7);"><img src="images/slider/fslider3_en.jpg" alt="slide 3"/></a>
<a href="javascript:ver_contenido(11);"><img src="images/slider/fslider4_en.jpg" alt="slide 3/"></a>

---

无法理解此JS:

<div  id="slider"  class="nivoSlider templatemo_slider">
<a href="javascript:ver_contenido(2);">
    <img src="images/slider/fslider1.jpg" alt="slide 1"/>
    <button type="submit" onclick="window.location('pdf\Catalog 2020-DEC PMEC-Final_compressed.pdf')">Download!</button>
    <a href="pdf\Catalog 2020-DEC PMEC-Final_compressed.pdf" download="Catalog 2020-DEC PMEC">Download</a>
</a>
<a href="javascript:ver_contenido(5);"><img src="images/slider/fslider2_en.jpg" alt="slide 2"/></a>
<a href="javascript:ver_contenido(7);"><img src="images/slider/fslider3_en.jpg" alt="slide 3"/></a>
<a href="javascript:ver_contenido(11);"><img src="images/slider/fslider4_en.jpg" alt="slide 3/"></a>

---

滑块JS文件：

<div  id="slider"  class="nivoSlider templatemo_slider">
<a href="javascript:ver_contenido(2);">
    <img src="images/slider/fslider1.jpg" alt="slide 1"/>
    <button type="submit" onclick="window.location('pdf\Catalog 2020-DEC PMEC-Final_compressed.pdf')">Download!</button>
    <a href="pdf\Catalog 2020-DEC PMEC-Final_compressed.pdf" download="Catalog 2020-DEC PMEC">Download</a>
</a>
<a href="javascript:ver_contenido(5);"><img src="images/slider/fslider2_en.jpg" alt="slide 2"/></a>
<a href="javascript:ver_contenido(7);"><img src="images/slider/fslider3_en.jpg" alt="slide 3"/></a>
<a href="javascript:ver_contenido(11);"><img src="images/slider/fslider4_en.jpg" alt="slide 3/"></a>