How to get inventory information for more than 50skus?

[qhangfan]

Thank you for developing such a useful SDK.
When I request it with the Inventories().get_inventory_summary_marketplace method, the returned nextToken value is null. How can I get nextToken?
Also I'm using Windows10 + python3.9 + pycharm, I can't find the file credentials.yml, In which directory should I create a new one? could you help me? thank you very much!