Detailed Implementation Guide for Per Use Billing?

I am not seeing the answer to this for some reason.
Say I have a product-
Shopping Addon (Per Use)

and the Shopping Addon is chained from another PA where images get generated (the shopping is of the objects identified in the image).

I don’t think that a subscription of 1 per month works, in case the user wants 2 or 3, etc. runs of this tool per month. The 1 subscription just expires with the first use, and doesn’t help with any subsequent uses…besides, the user has to pre-pay and is at risk for unused runs.

I also don’t think “up to 5” uses for $500 a month really works, because clients might be concerned…what if I have a slow month? what about the month I am on vacation?

So, I am looking for real per-use billing.

In the Stripe backend, I can edit the products:

Is this the correct setting? My idea is that with Daily billing, I stay current with customers.
The Metered Usage Charge Method has 4 values that seem pretty similar,

I think that sum is like “count” or the sum of the count(s), which for Daily billing is correct?

Is there an easier way to implement per use pricing?