file form 4868 - individual extension. must be postmarked by midnight on 4/18/2022. if you have a state income tax, that too may need an extension.
you can
1)e-file the federal using Turbotax
2) mail in the form https://www.irs.gov/pub/irs-pdf/f4868.pdf
3) Individual tax filers, regardless of income, can use Free File to electronically request an automatic tax-filing extension. https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free
4) if you owe you can use IRS Direct Pay - making an extension payment automay=tically extends your return without having to file for 4868 https://directpay.irs.gov/directpay/payment?execution=e1s1
if you need a state extension you can do that through Turbotax or possibly the state's department of revenue website
