Hi @illuarafath,
While it’s free to develop with our APIs and SDKs, we generally recommend a Pro (or higher) plan so that you can test out the most common functionality (certain features are limited to certain plans).
In regards to plans, licenses are applied on a user-basis. So, if the users utilizing your integration are under your Zoom account, you would be able to apply licenses to them yourself. If the users utilizing your integration would be under a different Zoom account, they would need to have their own licenses/plan.
You can find our plans’ pricing here:
Let me know if this helps to clarify!
Best,
Will