Well yea, google documentation for actions SDK, no comment.
Based on the example you provided these custom types belongs to the main structure in actions.json like:
"actions":[..],
"locale": "de",
"customTypes": [
{
"name": "$MorningOptions",
"items": [
{
"key": "6am",
"synonyms": [
"6 am",
"6 o clock",
"oh six hundred",
"6 in the morning"
]
}
]
}
]
If this is not working, you can try using types
:
"actions":[..],
"locale": "de",
"types":
[
{
"name": "$MorningOptions",
"entities":
[
{ "key": "6am", "synonyms": ["6 am","6 o clock","oh six hundred","6 in the morning"] }
]
}
]
Those are also in the main structure. But officially are deprecated:
https://developers.google.com/assistant/conversational/action-package/reference/rest/Shared.Types/ActionPackage#Type