Why not Discord's own log
Discord keeps an audit log, but it lives in server settings, it retains a limited window, it does not cover message edits and deletions, and nobody on your team is watching it. A log your moderators do not read only helps after something has already gone wrong.
Channel
Where events are posted. One dedicated channel, visible to moderators.
Pick this before you start ticking events — the plugin needs somewhere to write, and a configuration with events selected and no channel does nothing.
Choosing events
Events are grouped by what they concern: messages (edits, deletions, bulk deletions), members (joins, leaves, bans, unbans), roles, channels and threads.
Tick what you will actually read. The most common mistake here is turning everything on, discovering the channel is unusable within a week, and muting it — which leaves you with no audit log at all. Message deletions and member joins and leaves are the highest-value starting set for most servers; add the rest when you find yourself wishing you had it.
Exceptions
Three ways to narrow what gets logged. Leave them empty to log everything.
Ignore bots
Skips events caused by bot accounts and webhooks — usually the single biggest source of noise. Applies to message edits and deletions, joins and leaves, and bans.
Excluded roles
Members holding these roles are left out of the log. Applies to message edits and deletions, joins and leaves.
Excluded channels
Nothing that happens in these channels is logged, including threads inside them. Applies to messages, channel changes and thread changes.
Why the exceptions do not apply everywhere
This surprises people, so it is worth stating plainly rather than leaving to be discovered.
Bans and unbans are always logged, regardless of role exclusions. Discord does not reliably report the roles of somebody who has already left the server, so a role-based exclusion cannot be evaluated honestly — and silently skipping the event would be worse than logging it.
Channel, role and thread events are always logged regardless of the bot exclusion, because Discord does not report who caused them.
This is a limit of what Discord tells us, not a setting with a bug in it.
Free
Audit logging is free on every server, with no card and no time limit.