When you tap and hold a message you sent, you'll see these extra actions:
❤️ 👍 👎 😂 ❓❗ — Add or remove a reaction
Reply – Reply to your own message in the main chat
Thread Reply – Add more details in a side thread
Edit Message – Fix a typo or update your message
Copy Message – Copy your message to paste elsewhere
Flag Message – Report your own message (e.g. if you sent something by mistake)
Delete Message – Remove your message from the chat
Info – See when it was sent, edited, and who read it