I want to update my iPhone 6plus to iOS 12.5

Hi,

Did you follow this : https://support.apple.com/en-ie/HT204204 ?

You should be able to do this by going to Settings > Software Update > Install Update. You may need to free up space by deleting some apps or photos/videos prior to being able to complete the update.

Minor typo: Settings > General > Software Update > Install Update

Thanks for the catch! I missed that!

You’re welcome. Thanks for participating; see you in the lounge soon (8,000 pts)!