How to add image in post excerpt

Is it possible to add image in post excerpt without editing front mater

need a little more context/info to help you out here…

but lets make some assumptions that you’re trying to create a layout that is a blog roll (like something you’d find in WordPress) - you’ll do a for loop to loop through your posts, with an if else to display an image if it there is one being displayed in the front matter for each post. — I’m sure you’re looking for examples… but again need more context.