If someone says "be right back," it's usually an indication that they need to step away temporarily and will return shortly. In response, you can say something simple and polite to acknowledge their message. Here are some common responses:
- "Sure, take your time!"
- "No problem, I'll be here."
- "Alright, see you soon!"
- "Okay, I'll wait for you."
- "Take your time, I'll be patient."
These responses show understanding and indicate that you are willing to wait for their return. It's a polite way to acknowledge their temporary absence and let them know that you'll be available when they come back.