You can mute a chat conversation to stop receiving notifications while remaining in the conversation. This feature is available on Android only.
Muting a Chat in Android
To mute a chat conversation in Android:
Open a chat conversation. Messages are displayed in thread view.
Select ⋮ (the menu icon) in the top right of the screen.
Select Mute Chat.
In the Mute chat for... dialog, select one of the following mute duration options:
8 hours: Mute notifications for 8 hours (default).
1 week: Mute notifications for 1 week.
Always: Mute notifications indefinitely until you unmute the chat.

Optional: Select Show notifications if you want to receive notifications even while the chat is muted.
Select Mute chat to confirm.
The chat is now muted. You will not receive notifications for new messages in this conversation (unless "Show notifications" is enabled). The chat remains in your conversation list and you can still read messages manually.
Unmuting a Chat in Android
To unmute a chat conversation in Android:
Open a muted chat conversation. Messages are displayed in thread view.
Select ⋮ (the menu icon) in the top right of the screen.
Select Unmute Chat.
The chat is now unmuted. You will resume receiving notifications for new messages in this conversation.