That extension to file and pay federal taxes is automatic - you don't have to apply for it.
That extension was granted after TurboTax released its 2020 tax software, and it is automatic for anyone living in Texas. This means you won't have to file forms requesting more time to file.
If, however, you decide to file before June and don't want to pay any tax due until June 15. you'd have to select the "mail-in payment option" and "4/15/2021" as the payment date; the program won't be updated to show that Texas filers have an extra 2 months to pay.
See Extension and Tax Relief for Texas Winter Storm Victims for additional information.
Thanks - I hope people find that helpful. I realize it happened late, but would have been nice if TT had released a quick message on the screen saying how you could wait to file until June 15.