How to insert and display a PNG file as a Portfolio Item's title on a Portfolio gallery page?

I would like to insert and display png files (handwritten titles I've made) in place of the current portfolio item titles displayed on the main portfolio gallery page. Is there code I can use to accomplish this? Any help would greatly be appreciated. 

You could use custom css to add in a psuedo element for each title -- To target the exact sections on this page it would be helpful to have the site URL and password, but the you can follow these instructions to upload the images into your Custom CSS panel, and then use custom css to attach it to the title...

However to know exactly what to target we need access to the page!

You can also use some CSS (Design > Custom CSS) like this to achieve request 

.portfolio-grid-basic .grid-item h3 {
    color: transparent;
    background-size: cover;
    background-position: center center;
    display: inline-block;
}
.portfolio-grid-basic .grid-item:nth-child(1) h3 {
    background-image: url(https://cdn.pixabay.com/photo/2023/05/23/18/12/hummingbird-8013214_1280.jpg);
}
.portfolio-grid-basic .grid-item:nth-child(2) h3 {
    background-image: url(https://cdn.pixabay.com/photo/2023/06/10/05/11/himalyas-8053173_1280.jpg);
}
.portfolio-grid-basic .grid-item:nth-child(3) h3 {
    background-image: url(https://cdn.pixabay.com/photo/2023/06/12/05/12/bird-8057638_1280.jpg);
}

Replace Pixabay with your png url