What happened
An API key and a trade address serve different purposes. A request to check a recipient does not justify giving somebody developer credentials, browser cookies, or account approval codes. Before copying a value, identify what it actually is and why the recipient needs it. A helper describing every secret as a verification token makes the support process less clear, not more legitimate.
What to check
Use official Steam account and developer pages when reviewing credentials you personally created. Do not register a new key simply because a chat contact says it will fix a missing trade parameter. If an unfamiliar credential or account access worries you, use current official security and recovery guidance from a trusted device. Review the broader account situation rather than assuming deleting one key establishes that every session and device is safe.
Worked example
For example, a support impersonator asks for an API key to repair a trade URL whose token was truncated. The format issue requires obtaining the complete recipient address from your own settings, not generating a developer credential. In another case, the helper requests an authenticated session export for diagnostics. That grants a different kind of account access and should not be treated as an ordinary error screenshot.
Result and next step
A sound troubleshooting report contains the necessary recipient issue and public error, without access secrets. Describe what was requested and who asked, redacting any existing credential from attachments. If exposure already happened, begin official account security steps rather than accepting another unknown repair tool. Read Steam security recommendations and trade redirection guidance. Account access risks are broader than one API key, so avoid claims that a single deletion guarantees recovery.