Hi roni6382,
Thank you for posting in the Apple Support Communities. I see that you’re unable to complete the iOS update because it says Update Requested. I’d love to help.
First, if you're trying to update wirelessly, I suggest connecting your iPhone to a reliable Wi-Fi network, then trying to update again. From there, take each remaining step outlined in this support article: Get help with over-the-air iOS updates
If the issue continues, try updating via a computer with iTunes: Update your iPhone, iPad, or iPod touch
Be sure to back up your personal data to iTunes or iCloud before updating. Here’s how to backup: How to back up your iPhone, iPad, and iPod touch
I hope this helps get you started. Kind regards.