How can I change my iPhone version to iOS 15.1

This isn't a chat service, this is a user to user forum.

Update your iPhone, iPad, or iPod touch

• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.7

• If you have an iPhone 6S through 7, you can update to 15.7.3

• If you have an iPhone 8 or higher, you can update to 16.3.1

Go to Settings > General > Software Update.

This link will show you how to update your iPhone, iPad, or iPod touch using WiFi -

Update your iPhone or iPad - Apple Support Update your iPhone or iPad - Apple Support

This link will show you how to update using your computer -

Update iOS on iPhone - Apple Support Update iOS on iPhone - Apple Support

Spencerkush10 wrote:

Is there any help for this chat?

As this is a user to user support forum with Apple users such as your self, thus you may need to wait more than 30 seconds for a reply. Having said that, it appears you have already solved your tech support issue. If this is the case, well done.

This is not a chat service. What phone do you have? What is the current iOS version? Go to settings - general - software update and see what it says there.