The Echo Dot is currently sold old, and Amazon isn't even taking backorders. The product page wording is a bit unclear, almost as if it's not coming back:
"Thank you for your interest in Echo Dot. It is currently sold out. Stay tuned, we're always up to something new. Explore Amazon Echo or other Alexa-enabled products like Amazon Tap."
If it does become available again, you could do what I did to order one using an app called Roger: https://rogertalk.com/
Roger can be configured as if it were an Alexa device, which can then be used to order a Dot.
Thanks for the support!
We do not sell nor share any audio to third party, privacy policy here https://rogertalk.com/legal
If you have any other questions or concern, feel free to reach out to me https://rogertalk.com/ricardo