How to update ios 13 in iphone 6 plus

I have a iPhone 6+ and my last update is iOS 12.4.1 and I might have more updates or not for my iPhone 6+ and still waiting for more updates, but someone from my Apple iPhone class said that to update to iOS 13 you need to have the iPhone 7 and up. I only use my iPhone 6+ for emergency when I'm outside my home.

That is not possible, as it is not compatible.

You need a 6S or later to get iOS13.

While there could be possible versions of iOS 12 coming (e.g. 12.4.2), it is unlikely because iOS 13 is almost ready and it will be released for iPhone in 5 days.

You do not need the iPhone 7, you need the 6s or SE and newer for iOS 13. iPhone 6 or 6 Plus is too old and will not be supported anymore.