You can get a paid commercial support license for Oracle's JDK to get an extended maintenance window. But Oracle's publicly available builds don't require a paid license. However,they only provide public builds of the current Java version. If you want LTS, you have to pay them or use another vendors builds.
That's changed a bit. As of JDK 17, Oracle offers Oracle JDK builds under the NFTC license [1], free for use in production with updates overlapping the next LTS version.