Have you seen zabbix directory in /var/lib/grafana/data/plugins ? If no, remove plugin using grafana-cli and try to use implicit plugin dir option:
--pluginsDir "/var/lib/grafana/data/plugins"
--pluginsDir "/var/lib/grafana/data/plugins"
grafana-cli plugins install alexanderzobnin-zabbix-app --pluginsDir '/var/lib/grafana/data/plugins/' Incorrect Usage. NAME: Grafana cli plugins install - install <plugin id> <plugin version (optional)> USAGE: Grafana cli plugins install [arguments...]
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