Hey there map55,
Thanks for reaching out to the Apple Support Communities. We understand you're not seeing the option to enable two-factor authentication on your Apple ID, and we'd be happy to look into what's going on.
To get started, let's ensure that two-factor authentication is available your country/region. For help with checking that, take a look at this link here: Availability of two-factor authentication for Apple ID - Apple Support
If your location is listed, lets also ensure that you meet the minimum requirements for two-factor authentication with this next resource under the "Two-factor authentication" section: System requirements for iCloud - Apple Support
If two-factor authentication is available in your region, and you meet the minimum requirements, but are not seeing the option to enable two-factor authentication then we'd recommend reaching out to Apple Support directly from this link here: Get Support - Apple
We hope that's able to help.
Take care!