How to set up keyframes in animations?

Question

Angular

I want to loop the animation, but I can’t figure out how, I recently started learning angular

trigger( 'newDialog', [
        // void => *
        transition( ':enter', [
            animate( '', keyframes([
                style({  bottom: '0px', boxShadow: '0 0 5px rgba(0,0,0,0.5)', offset: 0 }),
                style({  bottom: '20px', boxShadow: '0 20px 20px rgba(0,0,0,0.1)', offset: 1 })
            ]))
        ])
    ])