The following setup focused to create a Default payment option on the Buy menu (Now/Later Payment) menu. If your purchase transaction wants the default setup as Later, this can make it easier for you when inputting invoices, you don't need to switch Payment (Now/Later) for each transaction. For detailed setup steps you can check the following article.
Step 1. Go to Setup, Click More Menu, then Select Module
Step 2. Go to Buy Tab, Set Default Payment, then Click Save
Step 3. Make Purchase Transaction to View the Result
If this setup has been done according to the method above, then when you make a Pay it will immediately display the Later option. So you don't need to manually change the payment from Now to Later.
You might also like to read this article :
If you want to apply the purchase method with 2 steps of verification, you can do it at DealPOS by configuring the setup, you can check the detailed explanation in this article : How to Activate Approval when using Buy (2 steps)
If you want to make a Purchase Return, you can read the article here : Purchase Return
If you just added a new outlet but can't make a purchase, it's probably that you didn't set the Enable Buy setting to Yes when you did so. You'll need to do some setup for that, and you can find a thorough explanation in the following article : How to Enable Buy Menu in New Outlets