miscellaneous.get_interstitial returns None instead of expected HTML

[asv-dev]

Hi there,
First of all, thank you for your hard work and contributions!

I encountered an issue while using the miscellaneous.get_interstitial method as it is returning None instead of the expected HTML.

Here's a reference to the relevant source code: miscellaneous.py#L80.

Steps to Reproduce:

Call the get_interstitial method from the miscellaneous module using a valid publishable_key.
Returned value is None.

Expected Behavior:

The get_interstitial method should return the appropriate HTML content as documented in Clerk Backend API Reference.

Additional Information:

I'm happy to assist in resolving this issue and would love to contribute a fix if you can provide any relevant guidelines for contributing to this project. Please let me know if there’s any additional information or setup needed to address this.

Thank you once again for your efforts and for maintaining this library! Looking forward to your response.