Step 1: Start by clicking on the lead.
Step 2: Proceed by clicking on payment or customer details.
Alternatively,
Step 3: Reach the same page by double-clicking the line item.
Step 4: Click on the edit button.
Step 5: Toggle the customer button to yes.
Step 6: Hit the save button.
After saving, the lead will now be a customer in the customer file.
Remember, a lead also becomes a customer when a quote is approved. In such a case, the lead will automatically convert to a customer.
