Engineering123

We use an industry-specific software to generate and send client invoices. Most invoices are paid via check but we want to give clients an electronic payment option. Before moving our website to Squarespace we used authorize.net to do this. Since our pricing is project-specific (not a per-item or per-service price) customers typed in the exact payment amount they owed to make a payment. So a client would receive an invoice for $1,000 and they would visit authorize.net via our website and type in that $1,000 amount to pay. Can we do something similar with Squarespace? It seems like the donation button works exactly in this way, but we are receiving payments, not donations.