Presuming you need to record all your sales transactions with every single detail, including your customer data, and you want to make the sell menu require Customer Information, you can set it to default, so the transaction cannot be made without customer information. To make the sell menu requires customer input, you can follow the steps below:
I. Configuration
Step 1. Go to Setup, Click More Menu, then Choose Module
Step 2. Go to Sell Tab, Set Customer Required to Yes, then Click Save
II. Try to Make a Transaction without a Customer
Go to the sell menu, and try to make a new sales transaction without inputting any customer in the customer input form
As you can see after the configuration was saved, you can no longer make a transaction in the Sell menu without inputting the Customer Information.
Related Article
If your store policy has a Salesperson in every transaction, you can provide a Sales Person Required configuration for each sales transaction Sales Person Required in Sell Menu
To prevent sales that exceed capacity/stock, we have a config that can help. Please check the following article: Configuration to prevent overselling in DealPOS App
You could also hide your Price with Price Visible Restriction