Once you have reached the File section of the return, you will select your refund method (if applicable), then you will be asked to check over your tax return. At the very end you will see a button on the screen that will say Submit my return(s) now, once you have selected that button your tax return has been e-filed and sent.
You can verify if your tax return is submitted by visiting the following TurboTax website e-file status lookup tool.
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