WhatsApp Web now has a built-in custom Sticker Maker feature that allows users to upload regular photos and turn them into stickers that you can send.
The feature could be accessed by selecting ‘Sticker’ from the attachments icon (paperclip) and then selecting an image to add.
See Screen Capture Below;

You can easily turn an image into the perfect sticker using a variety of editing options once it’s been uploaded.
Emojis, custom text, advanced cropping tools, and even the ability to layer more stickers on top of the one you’re working on are among the editing tools available.