How to force iPhone to upload to iCloud over mobile data Using iPhone 10.3.3 with no possibility of WiFi. Is there a way to force the use of mobile data to upload to iCloud?

I understand why the phone will not update using a potentially insecure signal but why won't it allow me to upload my photographs over mobile data?

These issues  are important to people making use of older lower end models. The #Iphone5c is still functional but with very limited scope because of the neglect over maximising use of mobile data and storage issues.
Go to:
Settings -&gt; Photos -&gt; Mobile Data
Then turn on the mobile data switch:

This will allow upload and download using mobile data.
Turn on Unlimited Updates to allow unlimited use of data to upload and download from iCloud when not connected to WiFi.
Beware to go exceed your mobile data plan.