To block a user without their contact:
- Navigate to the chats page
- Select a 1-1 chat with the user.
- Tap on their profile at the top of the chat.
- Scroll down to the bottom of the page and tap block.
To block a user through contacts:
- Navigate to contacts page.
- Select the contact you wish to block.
- Scroll down to the bottom of the page and tap block.