The only parameter that needs to change is the model name. You can reuse the same JSON as would originally have trained a model, to weight the fine-tuning deeper or to impart a known skill across models.
Here is a post with a script for fine-tune, also polling until success, needing only the JSONL file by its local name, and with other parameters up at the top (not attempting a validation file).
And just to show that you can upload the same filename, and even the identical file, multiple times:
if __name__ == '__main__':
file_id = upload_file(jsonl_file_path)
file_id = upload_file(jsonl_file_path)
file_id = upload_file(jsonl_file_path)
file_id = upload_file(jsonl_file_path)
Uploading file…
File uploaded successfully. File ID: file-gpkX51fSnjHYia40vFDL8acS
Uploading file…
File uploaded successfully. File ID: file-KXWKWEeiEodKKvgJixj2nzpF
Uploading file…
File uploaded successfully. File ID: file-HqvmFTlYQxCjiJZh6LMn3uzD
Uploading file…
File uploaded successfully. File ID: file-NAoIjftViXhEBKXnqiZ9TYaq