The app crashes when I try to create a POST request

[Onokaev]

Describe the bug
After changing the request method to POST and adding a request URL, the app crashes when I select the Request Body tab.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://developer.microsoft.com/en-us/graph/graph-explorer
2. Click on GET and select POST
3. Add an invalid Request URL: htps://graph.microsoft.com/beta/external/connections
4. Select the Request Body tab and see the app crashing

Expected behavior
App should not crash

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.