This is a diagnois code that you can scan with your phone
Your phone will then inform the server of your recent contact ids but it will pass no contact information whatsoever
People you have recently bumped into will be informed that someone they met has self-diagnosed.
If they scanned your contact information (blue code) then they will see that you have self-diagnosed.
You might want to contact people in your app directly and anyone else you have recently been in meaningful contact with.
Get well soon, and self isolate to avoid making any new contacts.