End-to-end encryption is a security feature that adds extra protection to messages and calls in a chat on Instagram. This feature ensures that only the sender and the recipient(s) of a message can see, hear, or read the content of the message, and no one else, including Instagram itself, can access it. End-to-end encryption is currently being rolled out for direct message conversations on Instagram. Users can activate end-to-end encryption for each of their conversations individually. To start an end-to-end encrypted chat on Instagram, users can follow these steps:

1. Open the Instagram app on their Android or iPhone device.
2. Tap the "Direct" icon in the top right corner of the screen.
3. Tap the "+" icon in the top right corner of the screen.
4. Select the recipient(s) for the chat.
5. Tap the toggle switch next to "Start end-to-end encrypted chat" to turn on the feature.
6. Start sending messages and calls with end-to-end encryption.

It is important to note that once end-to-end encryption is enabled for a chat, it cannot be disabled.