It should use the v3 api of edc for the asset creation <PROVIDER_DATAMGMT_URL>/management/v3/assets instead of <PROVIDER_DATAMGMT_URL>/management/v3/assets
The key "oauth2:clientSecret" is deprecated and should be replaced by "oauth2:clientSecretKey" which does not contain the secret itself but a reference to vault, where the key should be stored.
https://github.com/eclipse-tractusx/sldt-digital-twin-registry/tree/main/docs -> 4 -runtime view -> 1 (asset creation) has a deprecated example.
<PROVIDER_DATAMGMT_URL>/management/v3/assets
instead of<PROVIDER_DATAMGMT_URL>/management/v3/assets