Ok great. I assume this didn't originally work because it sort of "rolled over" all the employer info from my 2017 return when I DID get a W-2 from this company. I deleted this one and started a fresh new one, and now the option is there. Thank you!

You're welcome! Happy filing!

I entered a new W-2 and the substitute option is not there

Enter as much tax data as you can on the program W-2 and click on Continue.  On the following screen check the box for Substitute form and continue.  Follow the interview to complete this section.

Thanks Donin. I've updated my post with a screenshot to show that this option doesn't appear for me on the final page. Any idea why?

I could not get any of my test online tax returns give me the same screen as you posted.  They always showed the option for a Substitute form.
No ideas why you are not seeing the screen.
Could you send a 'token' of your return.  It removes all of your personal information and only sends the tax data.  I will forward the 'token' number to one of our TurboTax Moderators.  All I will need is the Token number of the file
Click on Tax Tools on the left side to the screen.  Click on Tools.  Click on Share my file with agent

Thank you @DoninGA!
Yes, @mr.bubbles.mb , a token will help us investigate further. Thanks 🙂

Ok, I shared my file with token# 500703

Thank you! We'll get back to you soon.