If your business requires that certain users are not permitted to issue refunds — for example, if your company policy requires a manager to authorise all refunds — you can enable a per-user restriction in the Back Office. When this restriction is active, the user will still be able to process exchanges, but will not be able to tender a refund back to the customer.
Setting up the restriction in the Back Office
1) In the Back Office, navigate to Setup, then Users.
2) Find the user you wish to restrict and click on the blue pencil icon to edit them.
Administrator access required
Only users with Administrator-level access can edit User settings in the Back Office.
3) In the Edit User panel, tick the Prevent Tendering Refunds? tickbox:

4) Click Save. The restriction will apply the next time this user logs in to the Point of Sale.
This setting is available across all Security Levels.
What a refund-restricted user will experience
A user with the Prevent Tendering Refunds? setting ticked can still process exchanges in the Point of Sale. The restriction only prevents them from tendering a refund back to the customer.
When a restricted user processes a return and reaches the reason code screen, they will only see the option to Process an Exchange (Return to POS & Edit Items). The option to proceed directly to a refund will not be available:

If a return transaction results in a negative balance — for example, if a returned item has not been replaced with an exchange item of equal or greater value — the Tender button will be greyed out and unavailable:

The user will need to add one or more items to the transaction to bring the balance to 0 or above before they can proceed to tender.