As is configured in your Fireblocks package, you are provided with a certain number of users in your account.
Note:
Usage counting pertains to all your mainnet workspaces, excluding API.
Once you have reached that number, it is no longer possible for you to add additional users, unless you either remove existing users, or reach out to our Customer Success to expand your user quota.
To obtain additional information on your account, including your user quota, and to upgrade to the next level, visit your Account page.