Welcome to the forum @ThaiMinh120
You will need to provide a lot more information
- What hardware/OS are you running node-red on?
- What version of node-red and of nodejs (use node -v to find that)
- What node have you installed to provide the firebase connection (possibly node-red-contrib-something)?
- Export those two nodes and paste them here. See this post for more details - How to share code or flow json
