Hi jimihendeix272,
Just to confirm, are you signed in with the same Apple ID for iMessage on both your iPhone and your Mac?
On your iPhone, check in Settings -> Messages. Make sure these settings are enabled:
- iMessage
- Send as SMS
- In Send and Receive: Make sure that you're signed into an Apple ID.
On your Mac, open the Messages app, then at the top of the screen, choose Messages -> Settings. Check the Apple ID tab.
If both devices are signed in to the same Apple ID, try signing out of that Apple ID on both devices, then sign back in. This should cause the Text Message Forwarding option to appear on your iPhone in Settings -> Messages.
You might also need both devices to also be on the same Wi-Fi network and have Bluetooth enabled.
Apple's guidance regarding this can be found here: Forward SMS/MMS text messages from your iPhone to your Mac or iPad - Apple Support (CA)