Thank for your good answer.
I am not using API Portal.
However, I was wondering if there was a way to register an OAuth client at the same time when registering an app using Portalman. This is because there was OAuth-related information in the Security tag in the message through Portalman.
What I wanted was to use the same APP key and OAuth Client_Id when registering the APP with a single registration.
[Partial text of App registration]
<l7:Security>
<l7:OAuth> <l7:CallbackUrl>https://HOST:8443/oauth/v2/client/authcode,https://HOST:8443
/oauth/v2/client/implicit</l7:CallbackUrl>
<l7:Scope>oob</l7:Scope>
<l7:Type>confidential</l7:Type>
</l7:OAuth>
</l7:Security>