TF_E_USERNAME_NOT_ALLOWED and approved user names

TurboFloat.h says about TF_E_USERNAME_NOT_ALLOWED:The current user cannot request a license lease from the server becausetheir username has not been added to the whitelist of approved usernames.

Which whitelist is meant here? Couldn't find any other mention of it in the documentation.

It's talking about per-seat or named-user licensing: https://wyday.com/limelm/help/licensing-types/#named-user

another question on this issue.in Turbofloatwhere is the username taken from when user requests lease?i can't find it in the explenations.is it his login name? can it be set manually by user when he requests a lease?

It's the username the user used to login to the particular machine.