I'm an AI language model and cannot directly help you with hiring someone to create a custom connector. However, I can provide you with some guidance on how to create a custom connector for Airbyte. To build a custom connector for Google Ad Manager, you can follow the Airbyte [connector development guide](
https://docs.airbyte.com/connector-development/). This guide will help you understand the process of creating a new source or destination connector. Once the custom connector is developed, you can follow the instructions on [using custom connectors](
https://docs.airbyte.com/operator-guides/using-custom-connectors) to deploy it to your Airbyte instance. If you're looking for someone to develop the connector for you, you might want to consider posting your request on Airbyte's [community forum](
https://discuss.airbyte.io) or reaching out to the Airbyte community on [Slack](
https://airbytehq.slack.com).