I have figured it out ... I've just added pointless data that I can ignore elsewhere in a normal SQL SELECT column, and kept the data that I need in the secondary column.

Here is the 'ALTER' statement:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER VIEW [dbo].[INF_GetWebOrder_JsonNoBillNoLines] AS
SELECT 
  dbassyOrderio.OrderNo AS 'OrderyNumNum',
  JSON_OBJECT(
    /*StaticDataStart*/
    'currencyCode': 'GBP',
    /*StaticDataEnd*/
    'phoneNumber':dbassyOrderio.Telephone,
    'email':dbassyLoggyLogins.Email
   ABSENT ON NULL) AS 'OrderishData'
FROM
    db_Orders AS dbassyOrderio
INNER JOIN 
    db_Logins AS dbassyLoggyLogins ON dbassyOrderio.LoginId = dbassyLoggyLogins.Id
GO

PERFECT!