Gupshup Template Based Attachment

Iam trying to use gupshup whatsapp business api through template.

My template expects a link url for the attachment therefore iam building an url through buffer in nodejs and having given response type for the link url as this.

       statusCode: 200,        headers: {            "content-type": "application/pdf",            'content-disposition': 'inline; filename=suresign.pdf',            'Accept-Ranges': 'bytes',            'Content-Length': buffer.length,        },        body: buffer.toString('base64'),        isBase64Encoded: true    }``` Iam able to generate message id ```{"messageId":"8427c6aa-8140-4d79-a835-ba8f44f6c867","status":"submitted"}``` but in gupshup callback response im getting error as this ```{    "app": "SureCredsLIVE",    "timestamp": 1654016941604,    "version": 2,    "type": "message-event",    "payload": {        "id": "8427c6aa-8140-4d79-a835-ba8f44f6c867",        "type": "failed",        "destination": "918553220750",        "payload": {            "code": 1011,            "reason": "Invalid Media Size"        }    } }```