How to make this structure in Json from SQL 2017?

I want to convert this structure by selecting data from the table when I select it, I am going to convert it into JSON from the Sql 2017 database. ATTACHMENT MY QUERY

Select Medio_Pago AS [medio_pago] from Table_FacturacionElect 
where Comprobante = '22'  FOR JSON PATH,WITHOUT_ARRAY_WRAPPER 

I wish to have this result excato

 "medio_pago": [
        "sample string 1"
      ],