Synology NAS and iPhone backups

[Enquiries]

Hi, I have a Synology DS920+ NAS and have been searching for how best to approach backing up iPhones to it, fairly unsuccessfully (getting the message that there is not enough room on my phone to backup to iCloud, and suggesting I pay Apple for more storage - a pain when there's loads of room on my Synology NAS....). The ideal use case would be to carry out the iPhone backup direct to the Synology NAS either via wifi or USB and bypass iCloud entirely.... realise that may not be possible else that would be the first thing that pops up in a google search.
Any advise greatly appreciated as to what is possible to automate....