The details are as follows.
1. Add trackers to torrent FDM. If enabled this option, trackers in list will be added to FDM downloading when task started.
It is helpful to find more peers from some well-known public tracker servers. The trackers list can be specified manually, or auto updated from a HTTP link. Supported tracker type includes HTTP, HTTPS and UDP tracker.
2. Update tracker list every day automatically.
If enabled this option, the trackers list above will be updated at FDM launch time and every 24 hours, by visiting the specified HTTP link.
An example of trackers list source is the open source project TrackersList, which provided severe trackers list collection. The address filled in the above snapshot is https://trackerslist.com/all.txt

Supplementary note, this is for BT download.
Tracker is a necessary role in BT download, it can effectively improve BT download speed.
Record user information downloading the same resource to help you establish connections with other users.
The more people use Tracker, the faster the BT download speed