This POST endpoint is used to initiate a load transaction, allowing you to add funds to a user token's wallet. To use this endpoint, you need to provide the user_token as a parameter in the URL Path. You also need to provide the client_load_id, source_token, and amount as JSON parameters in the Request Body. The client_load_id is a unique identifier for the transaction that you can use to track it, while the source_token is the token or account from which the funds will be loaded. The amount parameter specifies the amount of funds to be loaded into the user's wallet. The response will contain a JSON object indicating the status of the load transaction and any relevant details.