This is 100% possible to create dynamic prices for subscriptions.
Firstly, a subscription in Stripe is nothing more than a price which has the type parameter set to recurring.
Also, a price is simply attached to a product, and a product can have multiple prices attached to it…when a user is getting charged, all that is really needed is the price_ID so you can even charge different users different amounts for the same product, just depends on which price (ie: what price ID) you charge them with.
So, as long as you have your product already created, to create the dynamic price for the subscription, all you need to do is create a price with the create price api.
You can also use the subscription api to change a price of a subscription later in time…I do this to give a discounted subscription of 3 months before I change the price of the subscription to the normal price after the first 3 months.
If you need to fully understand how the Stripe API works, I have a course that has been available for a couple of years (and yes is still 100% relevant to how stripe api works today) that you might find valuable. It is a paid course that goes into great detail.