For a worker to have an identifier in their signature footer, they must have a State License credential included in their credentials list.
To add a credential to a worker, you must have the Individual Credentials permission. Once you have this permission, you can do it from the Workers panel by selecting the worker to whom the credential will be added. By clicking on the worker’s name, their profile will open, where on the right side you will find the Add Credential option, allowing you to add the required credential.
It can also be added directly from the Credentials panel > Individual. In the left-side filter, you can search for the worker, and in the upper-right corner, under the Add Credential option, you can add the corresponding credential.