The MediaGrid is a new supply curation and management platform, purpose-built for the next generation of programmatic buyers and sellers. The MediaGrid is part of Criteo (Commerce Grid), and this Trust Center page only describes opt-outs in general terms — it references "consumer rights portals" and "privacy settings" but does not link to an actual opt-out form or give a privacy contact address. You will need to follow the Trust Center's "Privacy" link to Criteo's privacy policy to find the real opt-out/consumer-rights tool, and because Criteo's opt-out is cookie/identifier-based it can lapse if you clear cookies or change browsers.