shut down my iPhone

See the following for the things you can do if Find My wasn't enabled on the phone: If Find My iPhone or Find My iPad isn't enabled on your missing device - Apple Support

anoud1e Said:

"shut down my iPhone: I want to shut down my iPhone its stolen and I don't have find my iPhone"

-------

Modify your Credentials:

Having so been stollen, consider modifying your credentials, ASAP, starting with a new password.

• Modify: your login credentials (using both a New eMail and a New Password) for Apple and each and all sites
• Associate: a different method of payment to your account
• Enable: Two-Factor Authentication for Apple ID PayPal and for all other accounts that have such an applicable option