H. RES. 1393 requires all full-time employees of the House of Representatives to undergo active shooter training once every Congress. These training sessions must be made available remotely, although staff members can choose to attend in person during the second session of the 119th Congress....
Simple Explanation
The bill wants everyone who works full-time in the House of Representatives to learn how to stay safe if there's a scary situation with a bad person, like an active shooter. It also says they can learn online if they want, and other people like part-time workers and interns can join too, but using tools they already have.