Hey again,
If you’re referring to the header background image on your home page you should be able to remove or reduce the opacity with some custom CSS. Please try adding the following CSS code in the style.css file of your child theme or add it in your site using the following plugin:
https://www.ads-software.com/plugins/simple-custom-css
.header-content-wrap {
background: rgba(0, 0, 0, 0.5);
}
This is black color with 50% opacity on it (you can find more information here https://www.w3schools.com/cssref/css_colors_legal.asp). Last numeric value represents opacity where 0 is completely transparent and 1 is full color. You can reduce it in order to make it lighter or set 0 in case you want to completely remove it and display only the image.
Hope this helps ??
Best regards,
Bojan