Apply wrapText to column with xlsx-populate.js

Question

I am generating an Excel file with xlsx-populate.min.js and using a plain archive as template. I iniciate the process with

    function getWorkbook() {
            return new Promise(function (resolve, reject) {
                var req = new XMLHttpRequest();
                var url = 'template_a.xlsx';
                req.open('GET', url, true);
                req.responseType = 'arraybuffer';
                req.onreadystatechange = function () {
                    if (req.readyState === 4){
                        if (req.status === 200) {
                            resolve(XlsxPopulate.fromDataAsync(req.response));
                        } else {
                            reject('Received a ' + req.status + ' HTTP code.');
                        }
                    }
                };

                req.send();
            });

    }
";

And write the values inside a promise after getting workbook

workbook.sheet(0).cell('M$jj').value('$obs');

The file is produced by generating a blob, so far ok.

I want to apply word wrap to a column starting from row 2 to the highest row.

Where and how should i call the richtext option.