The new feature needs users to update their app to the beta version.
The WhatsApp app has come up with a new update, where you can open chat without visiting the app.
This new feature is available in Android 2.18.138 and the users need to update their app to the beta version.
To use this new chat feature, WhatsApp's 1.5 billion active users need to type https://wa.me/(phone number) of the person they want to drop the text to. They will automatically be directed to the chat. If you want to use wa.me and you have an old WhatsApp version installed, you will be redirected to api.whatsapp.com in your browser.
The sticker album feature by Whatsapp is not made available and will be coming soon in the next release.