@Raj1 did you look at the link I posted for Pub 946. 

Assume whatever you want and do some research. https://www.irs.gov/publications/p946#en_US_2020_publink1000107703

Purchase Tax Tools as it has some excellent auto "tools"

The primary reason of this forum is answer software questions and specific tax questions, not to wander into every nook and cranny and other possibilities.