MoneyWiz uses MoneyWiz Cloud to sync your accounts, transactions and other MoneyWiz data among other devices. By default, it does not sync your transaction attachments (images and PDF files). If you wish to sync them as well, you'll need to connect MoneyWiz to Dropbox.
To sync your attachments, please do the following on all devices you wish to keep in sync. First you need to enter MoneyWiz Cloud section of the application. It's possible in one of the two following ways:
click on the round avatar icon at the top or
go to MoneyWiz Settings by clicking on the gear icon in the menu and then click on the first section that shows your e-mail.
Once there, click on "Receipt sync", select Dropbox and authenticate. Your images will be placed in the following location: Dropbox root folder/MoneyWiz.
You can now start adding attachments to your transactions (if you haven't done so already - MoneyWiz will sync previous attachments too). To begin, make sure that you've adjusted your Transaction layout settings to allow attaching images and just either edit exiting transactions or create new ones with attached images.
If your transaction attachments are not syncing:
Double-check that all devices are linked to your Dropbox account (see above).
Check if you did not run out of free space on your Dropbox account or reached the device limit (Dropbox Free tier imposes a 3 device limit).
Check if your Dropbox images folder contains the images you are looking for.
Open MoneyWiz on all devices and let them run for 2-5 minutes and check for any changes. If you did notice improvement, it means MoneyWiz is still uploading/downloading your images so please keep MoneyWiz open for bit longer.
A couple of notes:
it can take some time to upload all your attachments at first so please be patient,
there is currently no progress indicator as to how many attachments did MoneyWiz download or upload so please keep MoneyWiz open as long as you can see it actively uses Internet connection,
there is currently no way to change the location of the folder that MoneyWiz creates in your Dropbox,
you can only add images using MoneyWiz application - placing the photos inside "MoneyWiz" folder in Dropbox using macOS's Finder or Windows' Explorer or Dropbox website will not attach them to any transactions in MoneyWiz.