ksql create stream from json key/value - apache-kafka

Question

I have a problem with apache kafka and the output of connector.
when i try to create a stream from the topic i get some errors.
the data of the topic is this one ( without a schema, in json format ):
key:
{
"payload": {
"sourceName": "HotPump",
"jobName": "pollingHotPump"
}
}
value:
{
"payload": {
"fields": {
"cw": [
4657,
0,
0,
0,
0,
0,
0,
0,
0,
0,
13108,
16637,
0,
0,
0
]
},
"timestamp": 1638540457655,
"expires": null,
"connection-name": "Condensator"
}
}
the ksql query for create a stream is this one:
CREATE STREAM s_devices
(
key struct<payload struct<sourceName string>> ,
value struct<payload struct<fields struct<cw array>>>,
ts struct<payload struct<timestamp bigint>>
)
WITH (KAFKA_TOPIC='devices',
VALUE_FORMAT='JSON', KEY_FORMAT='JSON');
The result of ksql client is: "Failed to prepare statement: Cannot resolve unknown type: ARRAY"
When i try to create the stream only with key struct<payload struct<sourceName string>>
the select select key->payload->sourceName, value->payload->timestamp from s_devices;
working correctly and the value is showed;
when i try only with ts struct<payload struct<timestamp bigint>> the table is created but when i try to select the value is null select value->payload->timestamp from s_devices;
where is the error?
thanks