SOLVED Error with Slack (send image to channel)

[Hermes]

Last few days images give an error:
Data out
{
"ok": false,
"error": "invalid_blocks",
"errors > 0": "must be more than 0 characters [json-pointer:/blocks/0/alt_text]",
"warning": "missing_charset",
"response_metadata > messages > 0": "[ERROR] must be more than 0 characters [json-pointer:/blocks/0/alt_text]",
"response_metadata > warnings > 0": "missing_charset"
}
Data in:
{
"channel": "C01QARQ7L31",
"blocks > 0 > type": "image",
"blocks > 0 > title > type": "plain_text",
"blocks > 0 > title > text": "+31 6 phone name ",
"blocks > 0 > image_url": "https://.............jpeg",
"blocks > 0 > alt_text": ""
}

 

[Hermes]

Made an adjustment;

{
"channel": "C01QARQ7L31",
"blocks > 0 > type": "image",
"blocks > 0 > title > type": "plain_text",
"blocks > 0 > title > text": "+31 6 number name ",
"blocks > 0 > image_url": "https://........jpeg",
"blocks > 0 > alt_text": "Betreft "
}


error is now:
{
"ok": true,
"channel": "C01QARQ7L31",
"ts": "1616679295.001200",
"message > type": "message",
"message > subtype": "bot_message",
"message > text": "This content can't be displayed.",
"message > ts": "1616679295.001200",
"message > username": "Pabbly Connect",
"message > bot_id": "B01QM0J3FH8",
"message > blocks > 0 > type": "image",
"message > blocks > 0 > block_id": "Hqk",
"message > blocks > 0 > image_url": "https://.......jpeg",
"message > blocks > 0 > alt_text": "Betreft ",
"message > blocks > 0 > title > type": "plain_text",
"message > blocks > 0 > title > text": "+31 6 number name ",
"message > blocks > 0 > title > emoji": true,
"message > blocks > 0 > fallback": "900x1600px image",
"message > blocks > 0 > image_width": 900,
"message > blocks > 0 > image_height": 1600,
"message > blocks > 0 > image_bytes": 112907,
"warning": "missing_charset",
"response_metadata > warnings > 0": "missing_charset"
}

 

[Hermes]

So now no error, but a warning.
Problem was that the webhook had different parameters that alt_text was empty.