How to dowload Ios 13.0 on iphone 6 plus?

Unfortunately, the iPhone 6 Plus is not compatible with iOS 13 or higher.

That model can be updated to iOS 12.5.7, no further.

An iPhone 5s, iPhone 6, or iPhone 6 Plus isn't capable of 13 or above; they require at least 2GB of RAM.

(238531)

And without use ios how can i dowload a file

You can't, if the file requires a newer operating system than you have installed on the phone.

It is time for a new phone.