PocoDynamo does not appear to have the ability to update the definition of a DynamoDb table.
What is the best way to update the POCO and schema of an existing schema?
There’s no support for changing the schema of an existing DynamoDb table, most of the time you shouldn’t need to as the attribute values are dynamic but if you need to change any of the fixed schema like indexes you’ll need to copy it into a new table, some approaches are mentioned in this StackOverflow answer.