I’m not sure sure if you can access a seller’s balance using the Bubble Stripe plugin (assuming that’s the one you’re using) - I think you can only get your own account balance (I could be wrong there)…
But it’s certainly simple enough to do it using Stripe’s API and the API connector plugin, using a ‘retrieve balance’ call for the connected account.
If you’re not familiar with using the API connector, or Stripe’s API, have a look through this forum for more information, including this post: