How do I file electronically for the Economic Impact Payment for my son, who is an inmate. He has been incarcerated 5 years - unemployed.

[DanielV01]

He will have to file a 2020 tax return, even though he may not be required to do so.  If he has no official income to file, he may file a return claiming $1 in interest (which is how the non-filers' returns were reported before the website closed), and this will allow him to receive a credit for the stimulus payment.  

For more information, please see this webpage:  Non-Filers: Enter Payment Info Here Tool Is Closed