Yes, this can be done.
You need to send an http POST action that is constructed as below:
http://hubitat-ip-address:8080/installedapp/disable?id=app-id&disable=true
Replace app-ip with the app-id of your Alexa integration.
If you're doing this via Rule Machine, you can use "127.0.0.1:8080" in the URL instead of "hubitat-ip-address:8080"
To re-enable the app, use:
http://hubitat-ip-address:8080/installedapp/disable?id=app-id&disable=false
