Need help storing multiple databases

Hello I am Sai Anshuman i am 10 years I need your help and I am making a big app based on health if this question is already asked the sorry because i read trough it all and i could not find a similar question so my what i am struggling with is: I am have put 2 database API keys and 2 database URLs and when i test my app there is an error on database so somebody please help me and thank you for reading this.

Hello,

Why do you need multiple databases if you can create a single database where different users can only access their own nodes?

Which database are you using? airtable or firebase? you do realise that airtable allow you to have many tables with one API key access?