Paper Trading for each end user

Hello! I am working on integrating paper trading capabilities for our end users (through our app).

I got to a point where I am able to create accounts with the Alpaca Broker API, but I realized they don’t have any funding in them, even though Alpaca documentation states that paper trading accounts will have a default $100,000 on creation. This makes me think that the Alpaca’s Broker API is not actually paper trading.

My understanding is that Alpaca’s Broker API allows us to manage multiple accounts through Alpaca. But I’m not sure if this is considered paper trading. I understand that the sandbox environment would be a ‘simulation’ and thus a ‘paper trading’ environment, but It seems to be different from Alpaca’s paper trading endpoints.

Btw: I looked into instant_funding to be applied after account creation but it still needs an account source number.

Is there a way I can support each of our end users to create a paper trading account through Alpaca, and manage them as paper trading accounts? Including the default funding of their accounts when the account is created? Thank you!