Inserting images to Excel with pure JavaScript

Question

I'm currently exporting data to an xls file with alasql library, but I need to insert images to the same file.

I converted my image to base64 and added it to the JSON but shows pic related when exported:

I discarded the SheetJS library because this features are in the Pro Version (not free).

Edit 1

My current JSON object looks like this, as you can see the base64 is there (I was trying with a url too) :

Im creating my table with this alsql query, where I insert my JSON and the style :

 alasql('SELECT * INTO XLS("testo.xls",?) FROM ? as dato',[mystyle,$scope.datoXslx]);