Finish to fill up the return, but I do not find the button for "transmit my return now" ?

Click on File on the left side of the 2018 tax return online program screen.

You complete your tax return by finishing all 3 Steps in the File section.  In Step 3, to e-file your tax return, you must click on the large Orange button labeled "Transmit my returns now".  

After completing the File section and e-filing your tax return you will receive two emails from TurboTax.  The first email when your tax return was transmitted and the second email when the tax return has either been accepted or rejected.

I DID COMPLETED THE 3 STEPS AND EVEN  PAID $39.99 AND I DO NOT REMEMBER  SEE THE ORANGE BUTTON?

1. Select File in the left menu.
2. On the Just one more step screen, follow steps 1 and 2 if you haven't already.
3. Select the Start button to the right of Step 3.
4. On the Let's get ready to e-file screen, select I want to e-file.
5. Follow the instructions to e-file your return.