setChatLastSeen method
Implementation
void setChatLastSeen(
var currentUserId, var stCollection, var chatId, bool isChat) async {
//if (logInUser != null) {
await FirebaseFirestore.instance.collection(stCollection).doc(chatId).set(
{currentUserId: isChat ? true : DateTime.now().millisecondsSinceEpoch},
SetOptions(merge: true));
//}
}