Thanks for reaching out to the Community. I hope you're enjoying the day so far.
In QuickBooks Online, the Cash Flow statement is based on accrual basis accounting. Currently, we're unable to change it to cash basis or edit any preferences to classify a different method.
I understand how beneficial having the option to see the report in cash basis would be for you and your business, so I've gone ahead and submitted this suggestion to our Product Development Team. This way, our developers can review the feedback and consider it in a future update.
To stay on top of our product updates and feature releases, check out our Blog Site.
Please don't hesitate to let me know if you have any additional questions or concerns. Take care!