Good day, nicoletiszavolgy.
I'm here to help and share some information regarding opening JSON files in QuickBooks Self-Employed.
Could you please tell me what files are you trying to open? If you're trying to import and open bank statements via JSON files, this type of format is currently unsupported in QuickBooks Self-Employed.
You might want to convert the file from JSON into CVS or Excel format since these are the types of files that are supported in QuickBooks.
The following article contains information about importing and opening statements in CSV file format: Import transactions from other sources.
If you're referring to something else, please let me know. I'd be more than willing to lend you a hand.
