Paypal Error:Not a valid webhook URL

{
  "id": "WH-9YJ16368AL6057013-6DC39630JU8971338",
  "create_time": "2021-11-01T17:39:22.666Z",
  "resource_type": "capture",
  "event_type": "PAYMENT.CAPTURE.COMPLETED",
  "summary": "Payment completed for $ 23.99 USD",
  "resource": {
    "amount": {
      "currency_code": "USD",
      "value": "23.99"
    },
    "seller_protection": {
      "status": "ELIGIBLE",
      "dispute_categories": [
        "ITEM_NOT_RECEIVED",
        "UNAUTHORIZED_TRANSACTION"
      ]
    },
    "supplementary_data": {
      "related_ids": {
        "order_id": "1W5313654M9708630"
      }
    },
    "update_time": "2021-11-01T17:39:17Z",
    "create_time": "2021-11-01T17:39:17Z",
    "final_capture": true,
    "seller_receivable_breakdown": {
      "gross_amount": {
        "currency_code": "USD",
        "value": "23.99"
      },
      "paypal_fee": {
        "currency_code": "USD",
        "value": "1.36"
      },
      "net_amount": {
        "currency_code": "USD",
        "value": "22.63"
      }
    },
    "custom_id": "29b0b044-fbfe-4325-952e-20000d4a6caf",
    "links": [
      {
        "href": "https://api.paypal.com/v2/payments/captures/02335565G34798738",
        "rel": "self",
        "method": "GET"
      },
      {
        "href": "https://api.paypal.com/v2/payments/captures/02335565G34798738/refund",
        "rel": "refund",
        "method": "POST"
      },
      {
        "href": "https://api.paypal.com/v2/checkout/orders/1W5313654M9708630",
        "rel": "up",
        "method": "GET"
      }
    ],
    "id": "02335565G34798738",
    "status": "COMPLETED"
  },
  "status": "PENDING",
  "transmissions": [
    {
      "webhook_url": "https://www.meritofficial.com/webhooks/paypal/",
      "http_status": 400,
      "reason_phrase": "HTTP/1.1 200 Connection established",
      "response_headers": {
        "X-MiniProfiler-Ids": "[\"aad1e1f3-361e-479b-b26b-59d1691fc836\"]",
        "Server": "nginx/1.16.1",
        "Connection": "keep-alive",
        "Set-Cookie": ".Nop.Customer=37bbf8a9-3910-476a-9d27-73ac829aee03; expires=Thu, 03 Nov 2022 08:10:06 GMT; path=/; httponly",
        "Content-Length": "0",
        "Date": "Wed, 03 Nov 2021 08:10:06 GMT"
      },
      "transmission_id": "a9941940-3b3a-11ec-b750-f75a670c9758",
      "status": "PENDING",
      "timestamp": "2021-11-01T17:39:28Z"
    },
    {
      "webhook_url": "https://meritofficial.com/webhooks/paypal/",
      "http_status": 400,
      "reason_phrase": "HTTP/1.1 200 Connection established",
      "response_headers": {
        "X-MiniProfiler-Ids": "[\"9a29d3b9-4eb6-456c-9688-5c96be7f85af\"]",
        "Server": "nginx/1.16.1",
        "Connection": "keep-alive",
        "Set-Cookie": ".Nop.Customer=760e49c6-daed-4f15-8809-d26f4f00e72c; expires=Thu, 03 Nov 2022 08:09:12 GMT; path=/; httponly",
        "Content-Length": "0",
        "Date": "Wed, 03 Nov 2021 08:09:12 GMT"
      },
      "transmission_id": "a99021a0-3b3a-11ec-b750-f75a670c9758",
      "status": "PENDING",
      "timestamp": "2021-11-01T17:39:28Z"
    }
  ],
  "links": [
    {
      "href": "https://api.paypal.com/v1/notifications/webhooks-events/WH-9YJ16368AL6057013-6DC39630JU8971338",
      "rel": "self",
      "method": "GET",
      "encType": "application/json"
    },
    {
      "href": "https://api.paypal.com/v1/notifications/webhooks-events/WH-9YJ16368AL6057013-6DC39630JU8971338/resend",
      "rel": "resend",
      "method": "POST",
      "encType": "application/json"
    }
  ],
  "event_version": "1.0",
  "resource_version": "2.0"
}

What are you trying to do - Do you ave a question ?
What version of nopCommerce ?
What Paypal Plugin ?

Payments.PayPalSmartPaymentButtons error:

version:  nopCommerce version 4.40.3
plugins:  PayPal Smart Payment Buttons  Version: 1.19



View log entry details:
BraintreeHttp.HttpException: {"name":"VALIDATION_ERROR","message":"Invalid data provided","debug_id":"1b1572547f0e","information_link":"https://developer.paypal.com/docs/api/webhooks/#errors","details":[{"field":"url","location":"body","issue":"Not a valid webhook URL"}],"links":[]}
   at BraintreeHttp.HttpClient.Execute[T](T req)
   at Nop.Plugin.Payments.PayPalSmartPaymentButtons.Services.ServiceManager.HandleCoreRequestAsync[TRequest,TResult](PayPalSmartPaymentButtonsSettings settings, TRequest request)
   at Nop.Plugin.Payments.PayPalSmartPaymentButtons.Services.ServiceManager.<>c__DisplayClass29_0.<<CreateWebHookAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Nop.Plugin.Payments.PayPalSmartPaymentButtons.Services.ServiceManager.HandleFunctionAsync[TResult](PayPalSmartPaymentButtonsSettings settings, Func`1 function)