Add form fields to Checkout -> Payment&Review step

Question

is there any tutorial, documentation or hints how to add a custom form to the Payment&Review step for my custom offline payment module in Magento2 checkout process and how to connect it to the database? I have seen some tutorials that describe how to add fields to the shipping address (e.g. https://sohelrana09.wordpress.com/2015/11/28/how-to-add-custom-field-to-shipping-address-form-in-magento-2-onepage-checkout/) but that is no option for me because the solution should work even for products without shipping. Any ideas?

Thanks a lot

Answer 1

In this page of the docs you can find how to add a custom form.

That tutorial you linked can you also use to add fields to other parts of the shipping step btw. It doesn't have to be in the shipping address form.