Jinja expansion in handler names doesn't work

Host config sets sigsum_agent_user to seasalp.

root@sigsum-log-02:~# rg -- -\ name: /var/cache/ansible/collections/ansible_collections/sigsum/ansible/roles/sigsum_agent/handlers/main.yml
2:- name: "Reload systemd daemon (--user {{ sigsum_agent_user }})"
9:- name: "Restart sigsum-agent socket (--user {{ sigsum_agent_user }})"
17:- name: "Restart sigsum-agent service (--user {{ sigsum_agent_user }})"
25:- name: "Enable sigsum-agent socket (--user {{ sigsum_agent_user }})"
33:- name: "Enable sigsum-agent service (--user {{ sigsum_agent_user }})"

TASK [sigsum.ansible.sigsum_agent : Trigger handlers] **************************
ERROR! The requested handler 'Restart sigsum-agent service (--user seasalp-sigsum-agent)' was not found in either the main handlers list nor in the listening handlers list