Is any installation required?
Are there any other prerequisites?
Should “voice API” be Voice API?
Should the “Account setup” section actually be called “Application setup”?
After “Account setup” what is the next step?
In the video you actually use answer URL for both Answer and Event. Event URL should probably be different.
Placeholder typo “Kimblerly” probably should be Kimberley?
“By default, the talk action is synchronous.” - which means what?
“a synthesized speech message to a Conversation or Call” - do we explain the difference anywhere?
“you will need to use the full url including the hostname here of your webhook here.” could probably be worded better.
“Conferance” -> “Conference” spelling, check throughout.
“nexmo api” -> Nexmo API
The Details section for Hangup include a description for Earmuff a call - probably copy and paste error.
Ditto Transfer a call
<script type="text/x-red" data-help-name="createcall"><p>Transfer a Call to a new NCCO</p> - Description should be Create a call not transfer a call.
<p>PLay audio into a call</p> Typo on play.
<p>PLay text to speech into a call</p> - ditto.
<p>PLay DTMF into a call</p> - ditto
Initial look through:
https://github.com/Nexmo/nexmo-nodered/blob/master/README.md
https://github.com/Nexmo/nexmo-nodered/blob/master/auth.html
https://github.com/Nexmo/nexmo-nodered/blob/master/insight.html
https://github.com/Nexmo/nexmo-nodered/blob/master/ncco.html
https://github.com/Nexmo/nexmo-nodered/blob/master/sms_rest.html
https://github.com/Nexmo/nexmo-nodered/blob/master/vapi_rest.html
https://github.com/Nexmo/nexmo-nodered/blob/master/verify.html
https://github.com/Nexmo/nexmo-nodered/blob/master/webhooks.html