After seeing ‘Software update is required to connect to your iOS device’ what are the minimum macOS requirements, 10._ ? Currently running 10.11.6 and don’t want to up date to many versions Trying to connect to an iPhone running software Version 1

Read this. Maybe it will put your mind at ease. This will not update the Mac OS but it is required to update iTunes if you want to connect your phone to iTunes.

If you see "Software update is required to connect to your iOS device" on your iPhone, iPad, or iPod touch - Apple Support

Rob8888 wrote:

It is very vague, so it doesn't update the software on your computer nor iphone, just itunes?

That is correct. It is a minor update to iTunes only. I had to apply the update back when iOS 13 was released so my Mac which is also running El Capitan, 10.11.6, could see my iPhone and iPads. It took a few minutes to install and then my devices were able to connect to iTunes.

thank you for your help with this

You’re quite welcome.

It will simply update iTunes, not the MacOS itself

You need to accept the offered update.

You’re welcome.