Hi.
Here is a example `curl` command which registers a client with "Pre-Authorization" property set to "True":
```
curl -k -X POST -H "Content-Type: application/json" -d '{"client_name":"Test dynreg client","redirect_uris":["https://127.0.0.1:8080/login-redirect"],"response_types":["code","id_token"],"grant_types":["authorization_code"],"applicationType":"web","oxAuthTrustedClient": "true"}' 'https://your.gluu.host/oxauth/restv1/register'
```
It's possible thanks to oxAuth's feature allowing to specify additional properties you can set/edit with dynamic registration. Check "dynamicRegistrationCustomAttributes" field at "Configuration -> JSON Configuration -> oxAuth". "oxAuthTrustedClient" present there OOTB is the name of attribute representing "Pre-Authorization" property.
I'll see through that this is added to our docs, if it hasn't been yet.