For integrating with an ad server other than Google Ad Manager (GAM) to create an ad campaign, the consultant should recommend:

Creating a custom integration procedure to integrate with the ad server: This involves developing a tailored integration solution that communicates directly with the ad server's APIs, ensuring seamless data exchange and functionality specific to the client's needs.

Creating a custom solution using Apex code: Leveraging Salesforce's powerful programming language, Apex, to build custom logic and integrations that cater specifically to the functionality and workflows required for the ad server integration.

These approaches provide the flexibility and specificity needed to integrate with various ad servers, offering tailored solutions that meet the client's unique requirements.