MacBook Air microphone is not working. I can hear them. But, they can't hear me speaking.

I purchased a new MacBook Air 2 days ago. I have downloaded a CITRIX application so that I can work from home. But, during my 1st TEAMS meeting with the application of the same name, the team could not hear me. Most of the tutorials direct me to go to Sound and make an adjustment. However, the only thing I see when I go to the input tab is "MacBook Air Microphone." The online fixes direct me to look for the words "Internal microphone". I did see the the sound go up and down when I spoke, but, the team could not hear me and I know I was not on mute. Does anyone have a suggestion?