If you set Footer Image, and you need to change it to another image on a Product Page, you can follow these.
#1. Change Footer Image on All product Pages
You can use this code to Custom CSS box.
body[class*="type-products"] footer.sections img {
content: url(https://cdn.pixabay.com/photo/2024/05/19/13/27/daisies-8772617_1280.jpg);
}
#2. Specific Product Page
You can find Product Page ID.
In my example, it is: #collection-67b562fedf9c422667881c3c
You need to change it to this format: body.collection-67b562fedf9c422667881c3c
(replace # with body. )
Next, use this code to Custom CSS
body.collection-67b562fedf9c422667881c3c {
footer.sections img {
content: url(https://cdn.pixabay.com/photo/2024/05/19/13/27/daisies-8772617_1280.jpg);
}}