How to call function in store procedure using Sql Server 2014?

How to add auto increament with string of number and letter?

CREATE TABLE [dbo].[tbl_Product](

[Id] [int] IDENTITY(101,1) NOT NULL,

ProductId As 'PRO'+Right('000'+convert (varchar(10),Id),6)persisted,

[ProductName] [nvarchar](100) NULL,

[Quantiy] [int] NULL,

[Price] [decimal](18, 1) NULL,

[CreateOn] [datetime] NULL
) ON [PRIMARY]

 Output-