In Snapchat, you can not only send and receive photos and videos, but also communicate via video chat, namely, make and receive video calls (this feature was introduced in version 9.27.0.0). Snapchat video chat is free, but it consumes a lot of mobile data, so connect to a wireless network before making or receiving a video call.
Steps
Part 1 of 2: How to make a video call

Step 1. Update Snapchat
Chat got a new interface in version 9.27.0.0, which was released in March 2016. You must be running this or a newer version of Snapchat to use video chat. You can update the app in the app store of your device.

Step 2. Connect to a wireless network (optional)
Snapchat video chat is free, but it consumes a lot of mobile traffic. If your mobile traffic is limited, make and receive video calls only when your device is connected to a wireless network.

Step 3. Open the correspondence with the person you want to call
You can enable video chat from a chat with any of your Snapchat friends. Currently, Snapchat only allows you to make face-to-face calls.
- Recent conversations are displayed in the left pane. Swipe the correspondence from left to right to expand it.
- Also on this page you can start a chat with any of your friends. Click on "New Chat" (the icon in the form of a speech cloud) in the upper right corner and select the desired friend.

Step 4. Click "Video" to make a video call
The selected user will be made a video call. It is possible that the person will receive a call notification even if they are not currently using Snapchat (this depends on the Snapchat notification settings).

Step 5. Wait for the person to answer your call
If a friend's smartphone notifications are turned on, the device will ring even if Snapchat is not running. If notifications are turned off, your friend will only see the call if they are currently using Snapchat.
Your friend can choose from the following options. If you click View, your friend will see you, but you will not see him. If you touch "Join", you will see each other. If he clicks Ignore, your call will be dropped

Step 6. Swipe your friend's video to minimize it
Do this to open the chat controls. Click on the video again to expand it to full screen.

Step 7. Double-tap the screen during a call to switch from the front camera to the main camera (and vice versa)
Alternatively, you can tap a video on the screen and then select the Change Camera option.

Step 8. Press the "Smiley" button to add stickers to the chat
They will be added to the video stream for you and your interlocutor to see them.

Step 9. Press the "Video" button during a call to turn off the video chat
This will not end the chat - you will see the other person until you close the chat or until he or she hangs up.

Step 10. Close the chat to end the conversation
If your interlocutor does not hang up, close the chat to end the call. To do this, return to the page with the latest correspondence or open another application.

Step 11. Press and hold the Video button during a call to send a video message
Do this if the person is not answering the phone or you just need to send a short video message. This can record a 10-second video message that your friend will watch when they open the chat.
Part 2 of 2: How to receive a video call

Step 1. Turn on Snapchat notifications
Do this so you don't miss a single video call.
- Android - Launch Snapchat and click on the gear-shaped icon in the upper right corner. Tap Notification Settings and click Allow if prompted to enable Snapchat notifications. Check the boxes next to the "Enable notifications" and "Call" options.
- iOS - Launch Snapchat and click on the gear-shaped icon in the upper right corner. Tap "Notifications" and slide the slider next to "Call" to the "On" position. Now launch the Settings app, tap Notifications, find Snapchat in the list and activate notifications.

Step 2. Press "Watch" when you hear the call
This way you will see and hear your interlocutor, but he or she will not see and hear you.

Step 3. Click "Join" so that you and your interlocutor can see and hear each other

Step 4. Click Ignore to drop the call
The person calling you will be notified that you are busy.

Step 5. Click "Video" to turn off video chat on your side
You will still see the other person until they hang up or close the chat.

Step 6. Close the chat to end the call completely
To do this, go back to the page with the latest correspondence, open another application, or close Snapchat.