Unable to identify a valid form element. Try inspecting the HTML instead.

### Steps To Reproduce

1. Visit to [https://lucid.app/users/login#/login](https://lucid.app/users/login#/login)
2. Right click on the checkbox or "Remember me" text.
3. Select "Bitwarden | Copy custom field name"
4. Paste buffer now contains "Unable to identify a valid form element. Try inspecting the HTML instead."

Upon inspecting the HTML, there does not appear to be the usual form element name.

Is this a bug, or something that cannot be catered for by Bitwarden, or should this should be a feature request?

Regards.

### Expected Result

A copy of the form element should be in the paste buffer.

### Actual Result

Paste buffer contains "Unable to identify a valid form element. Try inspecting the HTML instead."

### Screenshots or Videos

N/A

### Additional Context

I don't this this is actually a bug, but rather a quirk of how lucid.app handles a checkbox.

### Operating System

Linux

### Operating System Version

Linux 5.15.0-79-generic #86-Ubuntu SMP Mon Jul 10 16:07:21 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

### Web Browser

Chrome

### Browser Version

Version 115.0.5790.110 (Official Build) for Linux Mint (64-bit)

### Build Version

2023.7.0

### Issue Tracking Info

- [X] I understand that work is tracked outside of Github. A PR will be linked to this issue should one be opened to address it, but Bitwarden doesn't use fields like "assigned", "milestone", or "project" to track progress.

Reproduce the issue at lucid.app/users/login#/login using Bitwarden's “Copy custom field name” action on the checkbox and “Remember me” text, then inspect the HTML as described. Trace the browser-extension entry point for that action and determine whether the checkbox markup can be identified; done means the expected custom field name is copied or the unsupported case is explicitly handled.

Written by the indexing model from the issue text.