If you are still stuck on Java EE 8 and missed the project’s evolution, it is important to note that in 2017, Oracle transitioned Java EE to the Eclipse Foundation. This move, coordinated with partners Red Hat and IBM, included the full reference implementation and the Technology Compatibility Kit (TCK).
The shift to Jakarta EE involves a critical breaking change: migrating all packages from the javax.* namespace to jakarta.* (necessary because Oracle retained the “Java” trademark). Some sub-packages were also renamed. To simplify this, you can use the Apache Tomcat migration tool for Jakarta EE, which automatically renames Java EE 8 packages to their Jakarta EE 9+ replacements.