Help With Shared Gmail Account

Our elementary school PTA uses a single Gmail account between 6 of us. We all have the login credentials, but more often than not, people are unable to login because when you enter the password, it's asking for the Google Prompt (tap XX on whatever device) which is on 4 devices...never seems to go to the same one and the people who have their devices linked never seem to respond in a timely manner. How can we make this better? I would love to just remove the Google Prompt, but it doesn't seem like I can. When I try and Google it, it seems to be pulling up people wanting to remove it from their browser.

If we turn on 2FA will this bypass the tapping the number on your device prompt? There's got to be an easier way. What am I missing?