Customer creation from Lead should restrict to duplication of customer name

ERPNext Selling/CRM
1

Creating Customer from Lead, but system allowing me to create same customer name again, this should be restricted to avoide confusion.
In customizr form I tick ti unique checkbox then also customer get created with the same name.

2

Try to add Server script to check and validate before insert.

if frappe.db.exists("Customer", {"customer_name": data.customer_name}):
    frappe.throw(_("Customer with name '{0}' already exists").format(data.customer_name))
3

Thank you Hardik for your reply. I tried this script but there is an error that customer already exists even if customer name is new.

4

Hello Hardik, this server script is working for me.
Thank you so much for your support.