Subscribing to PlayStation®Plus | PlayStation®4 User's Guide
Getting started with PS Plus | All you need to know about membership plans, PS Plus on PC, streaming and more (US)
PSN Card 500 HKD | Playstation Network Hong Kong digital for PSP, PS3, PSP Go, PS Vita, PS4, PS5 - Bitcoin & Lightning accepted
PS Plus Essential (US) is also being 30% discounted for new and returning members, if you only need Plus to play online, this is the time. : r/PlayStationPlus
PlayStation Network Card 50 EUR - price from $10.95 | XXLGamer.com
Sony $100 PlayStation Store Card [Digital] Sony PlayStation Store $100 - Best Buy