Are there any specific remembrances (adhkar) or supplications (du'a) to be recited when bidding farewell to friends, such as "Astawdi'uka Allah (I entrust you to Allah)" or "Fi Hifdh Al-Rahman (In the preservation of the Most Merciful)"?

The hadith indicates that greetings should begin and end with "salam" (peace), and this should also apply to phone calls and online conversations. There is no harm in bidding farewell by saying: "I entrust to Allah your religion, your trust, and the last of your deeds," following the example of the Prophet (peace be upon him). It is also permissible to use any good expression, such as praying for protection and success.