Alexa actionable notifications - I broke it and need help

I managed to get the alexa actionable notifications working, at least up to a point. I got as far as getting the correct response on the developer console when I said “open custom actions” ) i.e. "this is a test … I also got my alexa device to say something when I triggered it with a change in state of an entity (in my case a door opening, leading to the alexa saying "is that you?). After then trying to add a couple of automations and a script to get this all moving forwards, alexa now does not understand the command “open custom notifications” and in the developer console, it now just says “yes or no” instead of the “this is a test…”
Can anyone point me in the direction of where to look for a fix - I am not computer savvy so need help. I am using nabu casa, and a long lived token if that makes any difference. ChatGPT says my code in the developer console is missing code for LaunchRequest, but it has got some many things wrong (including instructions on how to set this up, which in the end I have ignored), I just don’t trust it any more. Thanks in advance for any help you can give