Which from the source data is available in ? Is it available in a text file , a JSON file or a CSV file? If it is available in any of these forms, you can use a file a connection in cloud application integration ( CAI ) to read this file and then write it to a CSV file. Please see if these KBs help in your use case:
You can get the API details from Power apps and the same can be used either through service connector or Rest V2 connector.