Online patching enablement is already present in 12.2.0 fresh install. Please proceed with 12.2.4 patches. I start with the 12.2.0 readme and apply the seed table upgrade patch first, then shutdown and apply any technology patches, then AD/TXK patches followed by 12.2.4. You should have used startcd 51 to save time on technology patching after the install.
Oracle E-Business Suite Release Notes, Release 12.2 (Doc ID 1320300.1)
Oracle E-Business Suite Installation and Upgrade Notes Release 12 (12.2) for Linux x86-64 (Doc ID 1330701.1)
Applying the Latest AD and TXK Release Update Packs to Oracle E-Business Suite Release 12.2 (Doc ID 1617461.1)
Oracle E-Business Suite Release 12.2: Consolidated List of Patches and Technology Bug Fixes (Doc ID 1594274.1)
Oracle E-Business Suite Release 12.2.4 Readme (Doc ID 1617458.1)
You should be looking at a higher version of 12.2 since 12.2.5, 12.2.6 and 12.2.7 are already released.
Thank you Michel.