Your software is up to date

• If you have an iPhone 6 or older, the highest you can update to is 12.5.3

• If you have an iPhone 6S or newer, you can update to 14.6

Update your iPhone, iPad, or iPod touch -

https://support.apple.com/en-us/HT204204

hi, go to the settings app, go to general, software update, and it will apear, download and install it and you should have no problem

sidenote, if your phone is older, you may want to check if it will slow down considerably when you update

hope this helps

holyschmoe

Why not? What happens when you try?

What model is your phone?