Hey Jorge,
Are you looking to completely remove all traces of invoices from your Method account?
If I recall correctly, you use QuickBooks Online which will not let you disable Invoices from syncing but you can customize Method to hide the invoices.
You will have to edit the CRMQBO_EditCustomer and CRMQBO_EditLead by removing the invoice option from the new transaction button and filtering the transactions grid to not show invoices (Step 3 in the grid wizard and add a filter to not show invoices).
Remove the Invoices tab link by going to customize > Tabs > Edit tab link for customers > Hide invoices tab link
If you use sales orders then you will need to remove the create invoice from the sales order screen (QBO_SalesOrder)
-- Loi