Electronic Filing of 2019 Tax Returns

I filed my 2019 returns by mail and neither the state or federal have been entered into the system.  I contacted my state and the representative says I should file electronically. I know that the returns were delivered since I received a return receipt from USPS.  I can't find a way to contact the IRS accept by waiting on the phone.

Does any know how to file 2019 Tax returns electronically? (My state is Maryland)