update ios 10xr backup not working no sp

1.

Try to free up iPhone device storage see this Apple articles below:

If you need more space for an update on your iPhone, iPad, or iPod touch

If you need more space for an update on your iPhone, iPad, or iPod touch - Apple Support

How to check the storage on your iPhone, iPad and iPod touch

How to check the storage on your iPhone, iPad and iPod touch – Apple Support (UK)

Clear Other storage on your iPhone or iPad

Clear Other storage on your iPhone or iPad - Apple Support

2.

What's the difference between device storage and iCloud storage?

What's the difference between device storage and iCloud storage? - Apple Support

See this Apple article: Upgrade to iCloud+ -< Upgrade to iCloud+ - Apple Support

See also: iCloud+ plans and pricing -> iCloud+ plans and pricing - Apple Support

3.

Which iPhone XS Max type do you have?

iPhone XS Max -> 64 GB, 256 GB, 512 GB

iCloud+ subscription -> 50 GB or 200 GB or 2 TB.

See -> How to back up your iPhone, iPad, and iPod touch

How to back up your iPhone, iPad, and iPod touch - Apple Support

If you back up to iCloud you need to upgrade iCloud+

If you back up to your PC (macOS or Windows OS) you need to have enough space.