In our old mapping system, all images and attachments were saved to a folder on our web server. The table was populated with the url. Would I be able to accomplish this workflow with Integromat and Survey123?
I haven't tried this but in theory it should be possible:
use HTTP GET to download the images.
use the FTP module to send them to your webserver
use HTTP Make Request to update your feature service with the path to folder on your webserver. Note: you will probably have to hard code the path to the virtual directory on your webserver. You can get the name of the actual file from when you do the HTTP Get request.
Hope this helps.
Have a look at this blog. I think you will find it useful - especially with updating your feature service: