Google Pay Integration, do i still need stripe

I am integrating google pay on my site and the problem I am facing is with the gateway object. I am not using any other payment gateway like stripe or anything. I want to do direct integration.

const tokenizationSpecification = {
  type: 'PAYMENT_GATEWAY',
  parameters: {
    'gateway': 'example',
    'gatewayMerchantId': 'exampleGatewayMerchantId'
  }
};