If you upload these to your document area, you should then be able to grab a URL (web address) for these. You may find it best to save these in the ‘Appended Text’ area in the Invoice Customisation section:
And then:
Adding the tag that I gave you above would add the images in, although you may need to play around with the width a little bit to make sure they all fit:
<img src="Put image URL here" style="width:120px;">
I’ve given the example of 120px, but you can play around with the figure there to suit your needs. Personally, I would do something like this, which would also center the images for you:
You can also play around with the code above to make sure it looks OK, before copying it across to your invoices (if you click ‘Edit on Codepen’ it’ll open in a bigger screen for you)
As always, if you need further help - please don’t hesitate to ask! 