All the settings sit in the scheduled task, not in the plugin. Go to System > Manage > Scheduled Tasks and open your ContentSync task. A setting marked PRO is shown as an upgrade badge in the free edition.

Source API Connection

• Source Site URL - the address of the site the articles come from, for example https://www.example.com. No /administrator and no /api behind it.
• API Key (Token) - the API token of a user on the source site. Your first sync shows where to find it.
• Request Timeout (seconds) - how long to wait for the source to answer. The default is 30.
• Verify SSL Certificate - checks the certificate of the source site. Leave this on. Only switch it off for a local or staging site that has no valid certificate.

Article Filters

The filters decide which articles the source hands over. They are explained in Choosing which articles to sync.

• Source Category ID - one category in the free edition, a comma-separated list in PRO.
• State Filter - published, unpublished, archived or all. The default is published.
• Source Tag IDs, Language Filter, Featured Filter and Workflow Stage - PRO.

Local Target Settings

• Default Target Category - the category on this site the articles go into.
• Use Category Mapping, Category Mapping, Tag Mapping, Author Mapping, Default Author and Access Level Mapping - PRO. See Categories, tags, authors and access levels.
• Unmapped Access Levels - what to do with an article that has an access level you created yourself and that is not mapped. The default is the safe one: the most restrictive level of this site.

Synchronisation Behaviour

• Dry Run (Preview) - go through a run without writing anything. See Dry run and logging.
• Force Resync - process every article again for one run, also the ones that did not change.
• Mirror Images - download the images of an article. On by default.
• Filter Article HTML - remove scripting from the article text before it is stored. On by default. See Security.
• Media Folders, Mirror Documents and Media and Maximum File Size (MB) - PRO. See Images, documents and media.
• Sync Custom Fields and Field Mapping - PRO. See Custom fields.
• Incremental Sync, Handle Deleted Articles and Action for Removed Articles - PRO. See Removed articles and incremental sync.
• Sync Schema.org Data - PRO. Copies the structured data of an article. Needs Joomla 6.2 or newer on the source.
• Rewrite Relative Links - PRO. Puts the address of the source site in front of relative links in the article, so they keep working on a site with other menu items. Links to files that were mirrored stay as they are.
• Batch Size - how many articles are asked for in one request. The default is 25. A lower number uses less memory, a higher number needs fewer requests.

Logging & Debugging

• Log Level - how much is recorded. Info is the normal setting. Choose Debug while you are setting things up.
• Write Log to File - also write the log to administrator/logs/contentsync.php.

The schedule

How often the task runs is a setting of the Joomla Task Scheduler, under Execution Rule in the same form. ContentSync has no schedule of its own.