Okay, I looked it up.
President * Biden signed an Executive Order on 01/21/2021 requiring face masks on commercial interstate travel He left it up to the TSA to implement the order.
Exactly, they tried to get Trump to issue a nationwide mandate and lockdown but he didn't take the bait and it never happened. There was never a national federal mandate and businesses who forced employees to wear masks are going to be facing big time endless law suits.