Error: DynamoDB ValidationException: Query condition missed key schema element

It means you're trying to run a Query using a condition that does not include the partition/hash key. In order to run a query in DynamoDB, you have to provide hash key of the primary index or secondary index.

For example, if you have a DynamoDB table with Partition Key called "index" and GSI (Global Secondary Index) with partition key called "email", you can only perform queries on these two, no matter how many other attributes your items in the table have. If you can't do that, use Scan operation instead since it can search for data on non-indexed fields.

You can also use our Query Builder - it will help you construct the query operation parameters which you can later paste into your application.