微信小程序怎么动态更换canvas中的lottie动画

Question

methods:{
 init() {
    this.ani = 'https://....'
    this.createSelectorQuery().select('#box').node(res => {
        const canvas = res.node
        const context = canvas.getContext('2d')
        lottie.setup(canvas)
        lottie.loadAnimation({
            loop: true,
            autoplay: true,
            path: this.ani,
            rendererSettings: {
                context
            }
        })
    }).exec()
 },
}

如上代码，该怎么样动态更换<canvas id="box"></canvas>中的lottie动画json