이미지 섬네일 URL.createObjectURL()

URL.createObjectURL(file[0]);

<input type="file"
	id="profilePic" class="rounded-circle pt-5"
	style="background-image: url('assets/img/messages-1.jpg'); 
    width:100px; height: 100px; background-size: cover;">
                
                
	const profilePic = document.getElementById('profilePic');

	profilePic
    	.addEventListener('change', function(){
		const url = URL.createObjectURL(profilePic.files[0]);
		profilePic.style.backgroundImage = `url(${url})`;
    });