/ppp secret set name=yyy numbers=[find name=xxx]
correct script way
/ppp secret set [find where name=xxx] name=yyy
extended syntax /ppp secret set numbers=[find where name=xxx] name=yyy
First, GET the .id: /rest/ppp/secret/name?name=xxx&.proplist=.id
(for example *5 )
Then PATCH that .id setting the new name: /rest/ppp/secret/*5
{"name": "yyy"}