Facing error: PayloadFormatVersion is a required parameter-API gateway and Openapi

Question

I am written YAML file using openapi 3.0.1 which i am trying to import in HTTP API gateway.But Facing issue/error though i have PayloadFormatVersion specified in YAML file

FYI. Trying to integrate api gateway with lambda proxy. Warnings found during import: Unable to create integration for resource at path 'POST /internal_links': PayloadFormatVersion is a required parameter for integration. Ignoring.

Please find attached opanapi YAML file. Let me know if anyone faced this issue earlier.

YAML

openapi: 3.0.1
info:
  title: internal link api
  version: '1.0'
  contact:
    name: XYZ
    email: [email protected]
  description: Exposes functionality to suggest internal links for existing customer sites.
servers:
  - url: 'https://api.gmail.com/v1'
paths:
  /internal_links:
    post:
      summary: return list of suggetion urls and anchor text.
      operationId: post-internal_linking
      x-amazon-apigateway-integration:
          type: AWS_PROXY
          uri: arn:aws:apigateway:us-east-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-2:accountid:lambda-handler/invocations
          httpMethod: POST
          passthroughBehavior: when_no_match
          credentials: arn:aws:iam::accountid:role/name
          PayloadFormatVersion: '2.0'
          #contentHandling: CONVERT_TO_TEXT
        #$ref: '#/components/x-amazon-apigateway-integrations/int-link-lambda'
      responses:
        '200':
          $ref: '#/components/responses/success-response'
        '400':
          description: Input parameter validation failed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/error-model'
        '401':
          $ref: '#/components/responses/unauthorized-response'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/error-model'
      requestBody:
        $ref: '#/components/requestBodies/request-body'
      description: Request to fetch urls which user can use to increase traffic on website
components:
  schemas:
    error-model:
      title: Common schema which is used to send erros responces.
      type: object
      description: A standard error object.
      x-tags:
        - Common
      # examples:
      #   - code: Error Code
      #     description: Error status code
      #   - message: Error Message
      #     description: Detail error message
      properties:
        code:
          type: string
        message:
          type: string
      required:
        - code
        - message
  responses:
    success-response:
      description: return JSON array of suggeted urls and anchor text.
      content:
        application/json:
          schema:
            properties:
              suggestions:
                type: array
                description: List of suggestions per the request
                items:
                  type: object
                  properties:
                    targetUrl:
                      type: string
                    anchorText:
                      type: string
                  required:
                    - targetUrl
                    - anchorText
            required:
              - suggestions
    unauthorized-response:
      description: Token validation failed.
      content:
        application/json:
          schema:
            properties:
              message:
                type: string
  requestBodies:
    request-body:
      content:
        application/json:
          schema:
            title: Internal Linking - Request v1
            type: object
            # examples:
            #   sourceUrl: 'https://service.mcafee.com/”'
            #   targetQuattrCategoryName:
            #     - Consumer Products
            #   targetNumber: 2
            description: Request for Internal Linking API
            properties:
              sourceUrl:
                type: string
                description: URL that will contain the new internal links.
                example: 'https://service.mcafee.com/”'
              targetQuattrCategoryName:
                type: array
                description: Target categories that should be linked to.
                example: '["Consumer Products-1","Consumer Products-2"]'
                items:
                  type: string
              targetNumber:
                type: integer
                description: Number of internal links desired.
                example: 3
            required:
              - sourceUrl
              - targetQuattrCategoryName