Up until now I've been submitting my quarterly VAT returns very simply, by logging in to my HMRC account and copying over the numbers in the relevant cells in my Excel accounts spreadsheet into Boxes 1-9 at HMRC. However, after 1 April I'll need to do this process 'digitally'

Now, I've come across an 'add-on' for Excel at https://appsource.microsoft.com/en-us/product/office/wa104381859 called 'VitalTax', which appears to be exactly what I need - apparently it links your spreadsheet to HMRC and then for each VAT return you simply enter the spreadsheet cell address for each of the 'Boxes', and at the click of a button it uploads them to HMRC. Just like what I do now, using copy-and-paste.
So, my query! Has anyone used VitalTax; and/or have any comments? I'm wary of installing random software but I would hope that the fact that it's sanctioned by Microsoft means it ought to be fine? I'm struggling to find any real user feedback about it online, so wondered if anyone here might be able to advise?