Check your Amazon Echo Dot software version

1. Open the Alexa app
2. Select Devices
3. Select Echo & Alexa
4. Select your device
5. Scroll to the bottom and select About, you’ll see your device’s software version

Current Amazon Alexa device software versions

https://www.amazon.com/gp/aw/help/id=201602210

Wikipedia on Amazon Echo devices

This can help you find what version your device is.

https://en.wikipedia.org/wiki/Amazon_Echo