Hi,
Yes, this is possible in Pickaxe. All you need to do is go to the Access tab of your Studio, navigate to the Products & Paywalls section, click Add Product, and then set your product frequency to one-time. From there, you can specify the credit amount users will receive.
This way, when a user runs out of credits, they can purchase that one-time product to top up.
Let me know if I understood your question correctly or if you’d like any help locating these settings!