Can't Figure out Books and level 2 payment data

Can't Figure out Books and level 2 payment data

Hello, I am having trouble figuring out how to collect level 2 payment data as required by my payment gateway. Last month it cost us almost $5000 in fees because of this. We are invoicing our clients with books and they pay through the link in that email and they have access to the customer portal. We are using authorize.net as our payment gateway, and it has been set up on that side of things but I can't figure out how to add the fields necessary and relay the information over to Authorize.net. The fields we need are PO Number, Tax Exempt, and Tax (which should already be there).

One thing to note is our company doesn't collect tax as it's a service and our clients are not tax exempt although we do strictly B2B sales. 

I have tried calling Zoho support and have gotten nowhere. I know this is probably a simple fix with the answer staring me in the face but I just for the life of me cannot figure this out. 

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