Paid / Debit to supply when purchase & Expense?

How to make a purchase can pay or debit to a specific supplier ?
How to track expense ?

I try to add more feature to my configuration of samba pos but i am not yet can do as i want :

-Purchase items to stock
-pay or debit to supplier
-Expense tracking
-Customer Debit , How to receive payment from customer after this ?
-How to make alert stock low qty?

All of your questions have already been asked and documented in the forum. Use the search function and youll find the info you need