Chrome, Edge, Yandex Browser, Opera

These steps also work for other Chromium browsers such as Brave and Vivaldi. There are three ways, pick one: the extension from the Chrome Web Store (recommended), the extension from an archive or the userscript.

The recommended way is the extension from the Chrome Web Store: from the store it installs in a couple of clicks and updates by itself.

1. Open the amo stickers page in the Chrome Web Store: amo stickers.
2. Click “Add to Chrome” and confirm the installation. In other browsers the button may be named differently.
3. Open or reload the amo tab: the sticker button will appear in the message input next to the emoji button.

In Edge, first click “Allow extensions from other stores” on the Chrome Web Store page; in Opera, install the “Install Chrome Extensions” extension — otherwise the browser won’t let you install an extension from the Chrome Web Store.

If you already have the extension from the archive, remove it before installing from the store. You will have to enter the GIF keys again, and your own bot token if you set one; stickers and packs stay: they are stored on the amo site, not in the extension.