I cannot install new software of 12.4.4 on my iPhone 5s.

See this for help with over the air iOS updates, Get help with over-the-air iOS updates - Apple Support

If that does not work, then connect the iPhone to a computer, running the latest version of iTunes and update that way.

I don’t know if this is related, but I note that your phone is in low power mode. It can’t be updated in low power mode.