Since Syncro does not let you upload images for use on invoice templates and the like, you will need to use some other site on which to host your images. Although many will appear to work when you add an image to your invoice template, when you go to an actual invoice and pull up the PDF, the image will not display.
The preferred solution is to host images on your own domain/website. This gives you the best level of control and privacy.
If you do not have your own domain on which to do this, your next option is to use some kind of file or image hosting site. We spent a lot of time testing image hosting sites and found that the majority of them are not compatible with our software. And some that do work sometimes display ads or content that is objectionable to some, such as porn. Others might be fine today but then later either stop working with our software, shut down, or start including objectionable content. For all those reasons, we do not list any recommended image hosting sites. Again, we recommend hosting them on your own domain.
However, we can say the below sites do not work with our software when it comes to displaying the images in PDFs such as invoices and estimates.