仅使用swift中的范围键查询AWS DynamoDB服务器

I am trying to use a query function on an aws dynamodb server and return the value of an index using only its range key. Basically I want a user to be able to find other users using only this range key. My program generates a random code from one user, and the other user is supposed to be able to find that user without knowing their user id and just knowing their random code. At the moment, when I query, it only returns users matching the same user id as the device that is querying, so I am trying to query for just the random code (which is the range key). Here is my code:I am trying to use a query function on an aws d