Nav bar disappears in embed mode

[huxihao]

Checklist

• [X] I have searched the existing issues for similar issues.
• [X] I added a very descriptive title to this issue.
• [X] I have provided sufficient information below to help reproduce this issue.

Summary

Embedding an app in iframe is a super useful feature supported by the official document. However, the navigation bar can not be rendered correctly in the embed mode. For example, add ?embed=true to the demo app URL will give:

https://st-navbar-1.streamlit.app/?embed=true&embed_options=show_toolbar

Reproducible code example

No response

Steps to reproduce

No response

Expected behavior

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Current behavior

No response

Is this a regression?

• [ ] Yes, this used to work in a previous version.

Debug info

• Streamlit version:
• Streamlit Navigation Bar version:
• Python version:
• Operating System:
• Browser:

Additional information

No response