in NXRM 2, there was a REST API ( /service/siesta/usertoken/current ) to retrieve your own user token value without using the UI.
This is useful in provisioning scenarios.
IQ Server has a REST API to generate and retrieve your own user token in one REST API call: https://help.sonatype.com/iqserver/automating/rest-apis/user-token-rest-api---v2#UserTokenRESTAPI-v2-CreatingaUserToken
NXRM 3 however does not have an officially supported way to achieve the same - get my own user token value via REST API.
NXRM 3 should implement a productized end user targeted and supported REST API to retrieve/generate one's own user token.
Attention Watchers: There remains no supported official REST API in NXRM 3 for this feature.
However for the adventurous we have documented an unofficial subject to change at any time method to achieve this ask in the following KB article:
Use at your own risk with the assumption that on any upgrade its usage could break.