I have found a possible solution since you said you already copied the .jar file over:
(With Eclipse and the project loaded)
1. Right-click on the parent project in the Eclipse Project Explorer tree
2. Go to Run As >> Run Configuration
3. Click the Arguments tab in the Run configuration window
4. In the VM arguments section, add the command "--add-modules java.xml.bind" (without the quotation marks)
5. Click the Apply button
6. Click the Run button, and test if working without error
Also, here are some additional solutions to try:
https://crunchify.com/java-11-and-javax-xml-bind-jaxbcontext/
https://crunchify.com/ideal-eclipse-ini-file-setup-for-your-eclipse-environment-best-practice-for-macos-and-windows/
Although, this post looks promising:
https://stackoverflow.com/questions/2037188/how-to-configure-eclipse-build-path-to-use-maven-dependencies