I haven't signed out a device in several years but I am pretty sure Apple sends you an email when you do that. I usually glance at it and then delete it, so you might have done the same. Also check your junk mail folder and you deleted mail folder (my service keeps messages for 30 days before finally deleting them). If you don't find it:
This support page has information about Apple support and service ➔ Contact Apple Support - Apple Support If live support options (chat and/or telephone) are available they will show near the bottom left.
- Telephone numbers may only work when calling from the same country.
- Chat options (telephone numbers appear as active links, not plain text) may depend upon cellular connectivity. If a number shows as an active link, click on it to see additional options.
- If chat is not available on the top level support page, try selecting your hardware and narrow down your issue to see if a support article offers a support link offering chat. For example, the contact support link on this page Check your Apple Account balance - Apple Support offers a chat link about emptying account balance even on a computer where the top level page does not offer any chat.
With an iPhone, iPad, or Vision, you may be able to chat using the Apple Support App if it is available in your country —> https://apps.apple.com/app/apple-support/id1130498044
