Sir How to use $in with Findone

Im new in mongo db , So I try to query last transaction with that have some string that in array
my code is

abc := []string{"A", "B", "C"}

filter =  bson.M{"age": m.age, "status": m.Status, "mode":  bson.M{"$in": abc}, "code": m.code}
option = created_at -1

@management_zabtech can you post more of your code, what results or errors you’re encountering, and examples of the data you’re working with?