Untitled fiddle

HTML

<!DOCTYPE html>
<html>
<head>
   <script src="https://cdn.jsdelivr.net/npm/hyperformula@3.4.0/dist/hyperformula.full.min.js"></script>
</head>
<body>
<h3>HyperFormula MOD sign vs Excel</h3>
<table id="out" border="1" cellpadding="6" style="border-collapse:collapse;font-family:monospace"></table>


</body>
</html>

JavaScript

const formulas = ['=MOD(-3,12)', '=MOD(5,-3)', '=MOD(-3,12)=9']
const excel = ['9', '-1', 'TRUE']

const hf = HyperFormula.buildFromArray([formulas], { licenseKey: 'gpl-v3' })
const values = hf.getSheetValues(0)[0]

document.getElementById('out').innerHTML =
  '<tr><th>formula</th><th>Excel</th><th>HyperFormula ' + HyperFormula.version + '</th></tr>' +
  formulas.map((f, i) =>
    '<tr><td>' + f + '</td><td>' + excel[i] + '</td><td><b>' + values[i] + '</b></td></tr>'
  ).join('')