You can easily save your 8-bit RGB Photoshop documents in the WebP file format. WebP format provides both lossless and lossy compression for working with images on the web.
To open and save WebP images directly from Photoshop, you can simply download and install the WebPShop plug-in.
You can download the WebPShop plug-in (with universal/ARM support) directly from Google who owns and maintains the WebP format. Also, WebPShop is available on GitHub under an Apache 2.0 license.