Parent issue: https://github.com/torrust/torrust-index/issues/586 Relates to: https://github.com/torrust/torrust-tracker/issues/850 We migrated from `config` to `figment` crate in the Tracker: https://github.com/torrust/torrust-tracker/issues/850. I think we could apply the same changes here.