How to get a Certificate Signing Request (CSR) File?

Follow the steps below to get the CSR file:

Step 1: Launch Keychain Access located in /Applications/Utilities.

Step 2: Choose Keychain Access > Certificate Assistant > Request a Certificate from a Certificate Authority.

Step 3: In the Certificate Assistant dialog, enter an email address in the User Email Address field.
Step 4: In the Common Name field, enter a name for the key.
Step 5: Leave the CA Email Address field empty.
Step 6: Choose “Saved to disk,” then click Continue.

Step 7: In the dialog box that appears, give the CSR a filename with the extension .certSigningRequest, choose a location to save it, and click the Save button.