1. Describe your performance in detail: describe your performance in detail in the certificate, including the nature, scale, time, impact and other information. You can use data, charts and other ways to show the specific situation of performance.
2. Provide evidence: If relevant evidence can be provided, such as customer feedback, sales data, project reports, etc. It can be attached to the certificate to increase its credibility.
3. Ask the leader to sign: If your leader doesn't sign the performance, you can ask the leader to sign it to prove the authenticity and effectiveness of the performance.
4. Ask colleagues to prove: If a colleague can prove your performance, you can ask them to sign the certificate, or provide a written certificate to increase the credibility of the certificate.