In the Search By Product name box, start typing Web Viewer and click on Web Viewer
Make sure Products is selected
Click on the first entry (all platforms are the same)
Click on 12.1
CA OUTPUT MANAGEMENT WEB VIEWER V12.1 S1409 - MEDIA REPLACEMENT
Right click on the .iso file and select mount to extract the .jar file. It will be in E:\InstData\Multiplatform for all platforms except for Windows. For Windows install file, the .exe file will be in E:\InstData\Windows_x64\NoVM.