You can find Keychain Access under Application, Utilities on your Mac
Step 2: Select your Pass Type ID Certificate
Make sure that you have the corresponding private key, you will also have to export it
Step 3: Export the Certificate and Key
Step 4: Save the P12 File
The File Format needs to be Personal Information Exchange (.p12). This file you'll have to upload in your user account to make use of your Pass Type ID with our service.
Step 5: Protect the P12 File
Enter a password to protect the certificate and key. You will use this password to unlock the p12 file when you upload it to our service.