If you owe, one of the steps in the filing process is to enter your account number for direct debit and pick a date. You can pick any date up to (but not after) July15. Or you can select “I will mail a check myself” and then transmit your return now but mail the check any time you want.
[edited 3/26/20] Please see update below
https://blog.turbotax.intuit.com/tax-news/is-the-tax-deadline-delayed-what-to-know-about-coronavirus-covid-19-and-your-taxes-46320/#federal-tax-updates