For Apple Health users, only the data from "Asleep" will be synced. Data from "Time In Bed" will not be used for the sleep goal. For more details, please visit: https://support.apple.com/en-us/HT211685
For Fitbit users, data from "Total Sleep Time" will be synced for the sleep goal. For more details, please visit: https://help.fitbit.com/articles/en_US/Help_article/1314.htm
For Garmin users, data from "Total Sleep Time" will be synced for the sleep goal. For more details, please visit: https://support.garmin.com/en-HK/?faq=plCzU0wYvU95ShBoA9afv6