Add Gradient to Background Image with CSS

CSS

header {
     text-align: center;
     background: linear-gradient(90deg, #d4eece, #55b3d0, #1e7eb7), url('../images/header-bg.jpg') no-repeat;
     background-blend-mode: multiply;
     background-size: cover;
 }

CSS

.cover {
     background: url('');
     background-blend-mode: multiply;
     background-size: cover;
     background-position: center;
 }
 .transparent-filter {
     background-color: rgba(0,105,142,.8);
 }