1. Open the keychain and select login and everything as shown in the figure?

If you already have a certificate and the certificate is valid, skip to the second step, otherwise?

Download, /certificationauthority/AppleWWDRCA.cer, and install.

Note: If it is not found in the search, it may be expired and hidden.

2. Select login in keychains, then click Certificates. In this interface, select View -> Show Expired Certificates on the toolbar. At this time you will find an expired "WWDR Certificate" (Apple Worldwide Developer Relations Certification Authority), delete it.

3. There is also this expired "WWDR Certificate" in the System (system item under login) column, delete it together.

4. As expected, your certificate has changed from "This certificate has an invalid issuer" to "This certificate is valid".

Note: Expired certificates in System and login must be deleted