Slack Modal message using web-hook not opening in the slack channel

I’m using a web-hook to post a modal interactive message in the slack channel but the message is not displayed in the slack channel

    var message={};
var attachments = [];
var attachment = {
"type": "modal",
"submit": {
    "type": "plain_text",
    "text": "Submit",
    "emoji": true
},
"close": {
    "type": "plain_text",
    "text": "Cancel",
    "emoji": true
},
"title": {
    "type": "plain_text",
    "text": "Your accommodation",
    "emoji": true
},
"blocks": [
    {
        "type": "section",
        "text": {
            "type": "plain_text",
            "text": "Please choose an option where you'd like to stay from Oct 21 - Oct 23 (2 nights).",
            "emoji": true
        }
    },
    {
        "type": "divider"
    },
    {
        "type": "section",
        "text": {
            "type": "mrkdwn",
            "text": "*Airstream Suite*\n*Share with another person*. Private walk-in bathroom. TV. Heating. Kitchen with microwave, basic cooking utensils, wine glasses and silverware."
        },
        "accessory": {
            "type": "image",
            "image_url": "https://api.slack.com/img/blocks/bkb_template_images/Streamline-Beach.png",
            "alt_text": "Airstream Suite"
        }
    },
    {
        "type": "context",
        "elements": [
            {
                "type": "mrkdwn",
                "text": "1x Queen Bed"
            },
            {
                "type": "mrkdwn",
                "text": "|"
            },
            {
                "type": "mrkdwn",
                "text": "$220 / night"
            }
        ]
    },
    {
        "type": "actions",
        "elements": [
            {
                "type": "button",
                "text": {
                    "type": "plain_text",
                    "text": "Choose",
                    "emoji": true
                },
                "value": "click_me_123"
            },
            {
                "type": "button",
                "text": {
                    "type": "plain_text",
                    "text": "View Details",
                    "emoji": true
                },
                "value": "click_me_123"
            }
        ]
    },
    {
        "type": "divider"
    },
    {
        "type": "section",
        "text": {
            "type": "mrkdwn",
            "text": "*Redwood Suite*\n*Share with 2 other person*. Studio home. Modern bathroom. TV. Heating. Full kitchen. Patio with lounge chairs and campfire style fire pit and grill."
        },
        "accessory": {
            "type": "image",
            "image_url": "https://api.slack.com/img/blocks/bkb_template_images/redwoodcabin.png",
            "alt_text": "Redwood Suite"
        }
    },
    {
        "type": "context",
        "elements": [
            {
                "type": "mrkdwn",
                "text": "1x King Bed"
            },
            {
                "type": "mrkdwn",
                "text": "|"
            },
            {
                "type": "mrkdwn",
                "text": "$350 / night"
            }
        ]
    },
    {
        "type": "actions",
        "elements": [
            {
                "type": "button",
                "text": {
                    "type": "plain_text",
                    "text": "✓ Your Choice",
                    "emoji": true
                },
                "style": "primary",
                "value": "click_me_123"
            },
            {
                "type": "button",
                "text": {
                    "type": "plain_text",
                    "text": "View Details",
                    "emoji": true
                },
                "value": "click_me_123"
            }
        ]
    },
    {
        "type": "divider"
    },
    {
        "type": "section",
        "text": {
            "type": "mrkdwn",
            "text": "*Luxury Tent*\n*One person only*. Shared modern bathrooms and showers in lounge building. Temperature control with heated blankets. Lights and electrical outlets."
        },
        "accessory": {
            "type": "image",
            "image_url": "https://api.slack.com/img/blocks/bkb_template_images/tent.png",
            "alt_text": "Redwood Suite"
        }
    },
    {
        "type": "context",
        "elements": [
            {
                "type": "mrkdwn",
                "text": "1x Queen Bed"
            },
            {
                "type": "mrkdwn",
                "text": "|"
            },
            {
                "type": "mrkdwn",
                "text": "$260 / night"
            }
        ]
    },
    {
        "type": "actions",
        "elements": [
            {
                "type": "button",
                "text": {
                    "type": "plain_text",
                    "text": "Choose",
                    "emoji": true
                },
                "value": "click_me_123"
            },
            {
                "type": "button",
                "text": {
                    "type": "plain_text",
                    "text": "View Details",
                    "emoji": true
                },
                "value": "click_me_123"
            }
        ]
    },
    {
        "type": "divider"
    }
]
};
attachments.push(attachment);
message.attachments = attachments;
print(JSON.stringify(message));

Hi @rohit.marathe,

Please send us the screenshot of your implementation so that we can understand the issue better.

Regards,
Yoga Ramya