[Smush Pro] Remove Filestack CDN

I have SmushPro CDN enabled but Google insight show that I need to ” Serve images in next-gen formats” and shows the reported images are served from cdn.filestackcontent.com which I don’t know how it is activated on my site.

Also, when I check those images on my site I notice that they were served from Smush CDN. Would you please help me to get rid of cdn.filestackcontent.com ?