When I go to settings on my iphone, there is no option to add family sharing.

Hi 8766kmh,

Welcome to the Apple (user-to-user) Community

You might want to check that you are signed in to your iPhone with your Apple ID: Sign in with your Apple ID - Apple Support

To share a subscription with a family member you first need to set-up Family Sharing: See: How to Set up Family Sharing – Apple Support

says:

"On your iPhone, iPad or iPod touch

✽ Go to Settings.

✽ Tap your name.

✽ Tap Family Sharing, then tap Set Up Your Family.

✽ Follow the onscreen instructions to set up your family and invite your family members".

and

Make sure that each family member has a unique Apple ID - Apple Support

Then: How to: Add a family member to your shared subscriptions

and

If Purchase Sharing is turned on, the family organiser will pay for everyone's subscriptions.

If you wish: How to share purchases with your family

More info:

What types of content can I share with my family? – Apple Support

Family Sharing website

Family Sharing - Apple

____________________

If you still need help accessing the settings:

Try re-starting your iPhone: Restart your iPhone

or

Wondering which iOS version is installed on your iPhone ... you may want to try updating to the latest version:

Eg: About iOS 16 Updates - Apple Support says iOS 16.4.1 is the latest.

All the best :-)