That was done through the TSA. The federal government does not have the authority to mandate mask wearing for every American and every business. There was never federal mandate for private businesses. Businesses across the country got to decide their mask policy and many chose to force their employees to wear masks all day even after there was volumes of evidence that masks do nothing to stop the spread of an airborne virus. These businesses are required to provide a safe workplace but they took it on themselves to require wearing a mask which in my opinion will soon be shown without a doubt to cause long term health issues. These companies should and will be sued on a massive scale.
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.