I use VeraPDF to validate PDFs (PDF/UA validation). This works fine and I get ValidationResult Object

ValidationResult result;

try (PDFAValidator validator = defaultInstance().createValidator(validatorConfig)) {
     result = validator.validate(parser);
    }

A ValidationResult Object has a lot of information like TestAssertation List. e.g.

{
  "TestAssertion": {
    "ruleId": {
      "specification": "ISO 14289-1:2014",
      "clause": "7.2",
      "testNumber": "34"
    },
    "status": "failed",
    "message": "Natural language for text in page content shall be determined",
    "location": "Location",
    "level": "CosDocument",
    "context": "root/document[0]/pages[0](334 0 obj PDPage)/contentStream[0]/content[0]/contentItem[2]",
    "locationContext": null,
    "errorMessage": "Natural language for text in page content cannot be determined"
  }
}

What I am trying to accomplish is to display a PDF in my Angular application using pdf.js and highlight areas that are causing the problem.