How to reply to a specific message on Instagram?
If you receive multiple messages from a person about different topics, you need to reply to individual messages, or the chat will be a mess. The receiver won’t understand which message you are replying to, and you will also forget it after a while.
That’s why Instagram introduced replying to messages like Facebook messenger. You can reply to a specific message using the Instagram application or web version. Your reply will include the original message at the top.
Reply to an Instagram message by swiping.
If you have the latest version of Instagram installed on your smartphone, you can access the fastest way to reply to a message. First, launch the Instagram application on your smartphone and click on the Chats icon at the top right corner.

Find the message you want to reply to. Tap on the message and swipe it right. It will select the message and take you to the reply box. Type your message and press the Send button. The receiver can see your reply and the message you replied to.
Reply to an Instagram message by tapping and holding.
Many users complained that they couldn’t reply to a message by swiping. That’s why you may try this method, as it’s available even if you don’t have the updated version of Instagram.

Open the Instagram app and tap the Chats icon from the top right corner. Then open chat with a friend. Tap and hold a message you want to reply to. A menu will appear at the bottom of the screen; click Reply. Type your message and press Send button.
Reply to an Instagram message on a Computer.

You can react or reply to Instagram messages using the web version. The web version has a dedicated Reply icon beside every message. Open a web browser on your computer and visit Instagram. Click on Messages at the left sidebar of Instagram, then open a chat with any friend you want. Click the Reply icon beside the emoji to reply to an individual message. Now type the message and hit the Send button to reply.