THE SOFTWARE IS CREATING INVOICES WITHOUT OUR KNOWLEDGE EVERY MONTH STARTING. HOW CAN I STOP IT?

I'm here to help you stop the recurring invoices, rvengw.

You can check the audit log if there are other users who create the invoice. If yes, you can delete the recurring transaction or edit the template in QuickBooks Online. 

Here's how:
 

1. Hit the Gear icon on the top menu.
2. Click Recurring Transactions.
3. If you’d like to delete the invoice template, select the Edit drop-down button and tap Delete.
4. Choose Yes to confirm.
5. If you’d prefer to retain the template, select Edit.
6. Change the Type to Unscheduled or Reminder.
7. Hit Save template.

Additionally, I've added these articles that'll help you on how to record invoice payments: Record invoice payments in QuickBooks Online.

Keep me updated in the comments if you have any other questions about recurring transactions. I'll be here to lend a helping hand.