Adding formula to cell not working

[toniojst]

Hi i succces download my html table to excel but problem is that script parse number by self. So i find that we can set the cell type and value. Also this i did sucessful bit then i want to add formula to cell and i dont get it to work. So what i missed up?

My code for now is:
Table2Excel.extend((cell, cellText) => { if (cellText == 'URE') { return { f: 'A1+A2' }; } else { return { t: 's', v: cellText } } });

Problem is that this cell is empty.