Build Errors (Maven and Gradle)

[EliotKhachi]

OS: Ubuntu 22.04, Linux 6.4.0
Gradle Version: 8.1
Apache Maven Version: 3.6.3
Java Version: OpenJDK 11.0.21

I'm having trouble building this project in Maven as well as Gradle. Any help would be appreciated.

gradle build yields:

A problem occurred evaluating root project 'sysml-v2-api-client'.
> Plugin with id 'maven' not found.  

Removing the plugin 'maven' line and running gradle build again yields:

A problem occurred evaluating root project 'sysml-v2-api-client'.
> Could not find method install() for arguments [build_5lgu73zj7q37wqjciaj1qbtdi$_run_closure7@112bf306] on root project 'sysml-v2-api-client' of type org.gradle.api.Project.

Not sure where to go from there. Hoping Maven would work, I added the following dependency to my pom.xml:

<dependency>
  <groupId>org.omg.sysml</groupId>
  <artifactId>sysml-v2-api-client</artifactId>
  <version>2020-09</version>
  <scope>compile</scope>
</dependency>

...yields the following error:

[ERROR] Failed to execute goal on project sysml-v2-api-client: Could not resolve dependencies for project org.omg.sysml:sysml-v2-api-client:jar:2021-09: Failure to find org.omg.sysml:sysml-v2-api-client:jar:2020-09 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced -> [Help 1]

Thank you in advance,
Eliot