Based on the otterkit package: https://github.com/otterkit/highlightjs-cobol, contains several improvements as of the writing: Better regex (several bugs fixed and minor optimization done), better TypeScript support, and AUTHOR has been added to the list of reserved words so it will be highlighted (just like IBM Z Open Editor's highlighter does).
Simply add highlightjs-enterprisecobol to your dependencies in your package.json (requires highlight.js to be installed). Install using npm
The official site for the Highlight.js library is https://highlightjs.org/
The Highlight.js GitHub project: https://github.com/highlightjs/highlight.js