Add section on private preview SDKs in readme

README.md

@@ -260,7 +260,7 @@ Stripe.enableTelemetry = false;
 Stripe has features in the [public preview phase](https://docs.stripe.com/release-phases) that can be accessed via versions of this package that have the `-beta.X` suffix like `25.2.0-beta.2`.
 We would love for you to try these as we incrementally release new features and improve them based on your feedback.
 
- To install, choose the version that includes support for the preview feature you are interested in by reviewing the [releases page](https://github.com/stripe/stripe-java/releases/) and then use it [installation steps above](#installation).
+ To install, pick the latest version with the `beta` suffix by reviewing the [releases page](https://github.com/stripe/stripe-java/releases/) and then use it [installation steps above](#installation).
 
 > **Note**
 > There can be breaking changes between two versions of the public preview SDKs without a bump in the major version. Therefore we recommend pinning the package version to a specific version. This way you can install the same version each time without breaking changes unless you are intentionally looking for the latest public preview SDK.
@@ -270,6 +270,9 @@ Some preview features require a name and version to be set in the `Stripe-Versio
 ```java
 Stripe.addBetaVersion("feature_beta", "v3");
 ```
+### Private Preview SDKs
+
+Stripe has features in the [private preview phase](https://docs.stripe.com/release-phases) that can be accessed via versions of this package that have the `-alpha.X` suffix like `25.2.0-alpha.2`. These are invite-only features. Once invited, you can install the private preview SDKs by following the same instructions as for the [public preview SDKs](https://github.com/stripe/stripe-java?tab=readme-ov-file#public-preview-sdks) above and replacing the term `beta` with `alpha`.
 
 ### Custom requests