Why is lazy loading not stopping HTML Images from loading?

I am working with a clients website, he wanted his 139 pictures added to his project page and the site takes forever to load, doesn’t load all images, I added lazy load into the IMG tags and it still takes forever. I NEED THESE IMAGES TO LOAD UPON SCROLLING THROUGH THE GALLERY GRID.

<div class="project-item">
<img src="Projects/1.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">

<img src="Projects/2.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/3.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/4.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/5.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/6.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/7.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/8.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/9.jpeg" height="250" width="175" alt="projects" loading="lazy" />

</div>
<div class="project-item">
<img src="Projects/10.jpeg" height="250" width="175" alt="projects" loading="lazy" />