Braintree: I can't modify any fields

I can't seem to be able access any of the fields to modify them

In fact, I'm not sure what you are referring. If you mean to change product details within braintree integration, please note that I was able to that as you can see here. I cloned your form  and made these changes on my side. 

 

If this is not the issue, could you please provide us some more information. 

Waiting for your return. 

can I use it with a different payment gateway?
Thank you
...

It is allowed to use only one payment integration per form. If you would like to use another payment integration together with Braintree, It is unfortunately not possible. 

On the other hand, you can clone your current form and change payment integration on the cloned form. I think it is the only way to collect payment through different payment gateways for the same products. 

Here is the guide about how to clone a form.

https://www.jotform.com/help/42-How-to-Clone-an-Existing-Form-from-a-URL

Hope, these would help you. If not, please do not hesitate to contact us. 

thank you - I understand that I can't use two separate payment methods -
I would like to not use braintree at all - is that possible using this
form? Can I change the gateway?
...

You would need to remove Braintree first then drag your next preferred payment gateway in the form. If you are on the version 3 builder, you will be asked if you want to keep your product items. Just please select yes and then drag the new payment field. The items will be automatically added after.

If you are on the version 4 builder, you won't be asked about keeping the items. The form builder will automatically keep/add it for you.