Open Instagram and go to your Direct Messages
Tap the message you want to reply to
Type your response in the message box
Tap Send
To reply to a specific message in a chat, press and hold the message
Tap Reply
Type your response
Tap Send
To react to a message, press and hold the message
Select a reaction
To respond to a story message, open the story reply in your DMs
Type your reply and tap Send
To reply with a photo or video, open the chat
Tap the camera or gallery icon
Select or capture media
Tap Send
To reply to a message request, open Message Requests
Open the request
Type your response
Tap Send