If you already have your SSL Certificate and just need to install it, see
Oracle Wallet Manager SSL Certificate Installation.
How to generate a CSR using Oracle Wallet Manager
In Oracle Wallet Manager, choose Operations from the menu. Select Create Certificate Request to open the Create Certificate dialog box.
Enter the following information in the required fields:
Click OK. A dialog box will tell you that a certificate request was successfully created.
Click OK again to return to the main window.
In Oracle Wallet Manager, choose Operations from the menu. Select Export Certificate Request.
Enter the directory where you want to save the CSR. Enter a file name in the Enter File Name field.
Click OK. You can now open the CSR file you generated in a text editor and paste the contents in the certificate ordering process.
After you receive your SSL Certificate from DigiCert, you can install it.