Justin, as a manager with the ITA team, should seek approval from the appropriate stakeholders within his organization before implementing any modifications suggested by the client. The specific individuals or departments involved may vary depending on the organization's structure and processes. Generally, Justin should consult with his immediate supervisor, project manager, or other relevant decision-makers within his organization to obtain approval on the modified terms proposed by the client. It is important to follow the established protocols and hierarchy within the organization to ensure proper review and approval of any changes.