How to change STRING_AGG to stuff xml to split feature value by pip?

select
   a.RecomendationId,
   cast(STRING_AGG(cast(f1.FeatureValue as varchar(300)) ,'|')  WITHIN GROUP (ORDER BY f1.FeatureId ASC) as varchar(300)) AS DiffFeatures
 into ExtractReports.dbo.TechnologyOriginalFeaturesEqual
 from extractreports.dbo.partsrecomendationActive a 
 inner join ExtractReports.dbo.TechnologyPlPartsFeaturValuesOrg f1  on f1.partid = a.OrignalPartId
 inner join [Technology].Receipe Ft  on ft.featureid = f1.featureid and ft.operatorid = 1
 group by a.RecomendationId

 create table ExtractReports.dbo.TechnologyPlPartsFeaturValuesOrg
       (
       ID int identity(1,1),
       PartId int,
       FeatureID int,
       FeatureName varchar(200),
       FeatureValue varchar(200)
       )
    
 create table extractreports.dbo.partsrecomendationActive
 (
 RecomendationId int identity(1,1),
 OrignalPartId int
    
 )
    
 CREATE TABLE [Technology].[Receipe](
     [ReceipeID] [int] IDENTITY(1,1) NOT NULL,
     [FeatureID] [int] NULL,
     [OperatorID] [int] NULL,
 PRIMARY KEY CLUSTERED 
 (
     [ReceipeID] ASC
 ))