How to set background image for header?

How can I set background image for the <ion-navbar> component?

.toolbar-background {
    background-image: url('')!important;
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;

I Use all these methods but i am unable to change the background-image and background- color in ion-header and ion-navbar in ionic3. please help me.

I think this may help i set image to my side menu header

	<ion-header padding="true" >
        <ion-toolbar color=dark >
			<ion-title  >
			<img  object-fit: cover src="../assets/imgs/logo2.png" >

this solution worked for me