How to make "auto-prepare:true" using rest API

Couchbase Server
1

curl http://127.0.0.1:8093/admin/settings -u Administrator:*****

{“auto-prepare”:false,“completed”:{“aborted”:null,“threshold”:1955},“completed-limit”:4000,“completed-threshold”:1955,“controls”:false,“cpuprofile”:"",“debug”:false,“functions-limit”:16384,“keep-alive-length”:16384,“loglevel”:“INFO”,“max-index-api”:4,“max-parallelism”:1,“memprofile”:"",“mutexprofile”:false,“n1ql-feat-ctrl”:12,“pipeline-batch”:16,“pipeline-cap”:512,“prepared-limit”:16384,“pretty”:false,“profile”:“off”,“request-size-cap”:67108864,“scan-cap”:512,“servicers”:16,“timeout”:0}(base)

this was the result; but how to make it autoprepare:true

2

https://docs.couchbase.com/server/6.5/settings/query-settings.html

At service level:
        You must set for each query service and it will not persist (i.e. will lost on restart, you must set again)
         curl http://hostname:8093/admin/settings -d '{"auto-prepare":true}' -u user:pword

You can also set per request auto_prepare=true like any other request level setting https://docs.couchbase.com/server/current/settings/query-settings.html#section_nnj_sjk_k1b