Remove url from tag samlp

Help
,
1

I am using auth0 with salesforces integration

my salesforces inregration akm me to add a field to smal files with portal_id with fixed vars

i hae create a rules with this lines

  context.idToken['portal_id'] = "XXXX";

this works but this add

  <saml:Attribute Name="http://schemas.auth0.com/portal_id" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">

i need to remove “http://schemas.auth0.com/”