Customers is not showing in the Tickets

Dear Frappe Team,
Greetings of the day

We are using Frappe Helpdesk to resolve the customers tickets. We have created the customers in the HD Customer doctype but these customers are not able to view in the Customer drop-down of Ticket.Any one can help me on this.Your quick response is highly appreciated

Thanks And Regards
Sk.Khaja Kareem
9014040855

@rmehta
Please Give me any solution on this.

Thanks and regards
Sk.Khaja Kareem