Hopefully someone that knows how to do it will post as I dont really know if it can be done.
There is this similar thread see here.
Setting up a switch as doorbell to activate a camera on amazon echo display - Apps & Services / Amazon Alexa - openHAB Community
I believe Alexa can show a jpg or a mp4 recording, but the issue is starting a live feed as you need RTSP or WebRTC to do it and it needs to be via HTTPS with a valid signed cert.
If you want 2 way audio then you must use webRTC according to the Alexa API docs.
I saw some people mention using https://voicemonkey.io/ on the web to trigger routines and send video, but my guess is it may need to be mp4. The ipcamera binding can create mp4 recordings from any camera that has a rtsp feed or other type of feed that ffmpeg can use.
Its also difficult to know if this is possible to do in all countries as some of the Alexa stuff only works if you select your in a country they allow the feature to work in.
With Google Home and Chromecast devices it is easy to do as they support HLS streams which the binding can create. Using a tablet on the wall with the main UI and a widget is probably a better long term alternative and may end up cheaper.