just add the bg-faded class to either the first <div> (if you only want the background behind the ribbon box and not the credit line) or create another <div> around the whole snippet and add the bg-faded class to that one! (if you want it behind the ribbon box and the credit line)

you're using custom CSS so i can't actually tell for sure if bg-faded is the one you need, but if it's not that it's probably bg-dark or card or it's inline CSS, like style="background: #000000" (replace 000000 with whatever color the other boxes are using).

you'll also probably want to add some padding so that the background isn't right up against the edges of the ribbon images & text. here's the bootstrap documentation page on that if you aren't already familiar with how to do that! the exact class for that will depend on exactly what you want so you should give it a read yourself and try, but if you need help with that let me know :]