I think that the support ticket route isn’t as effective as it should be for FPs.
It would/should have been much quicker to submit it from avastUI - presumably it was added to the virus chest - in which case it can be submitted directly from there.

If you didn’t allow it to be added to the chest, you can add it manually and then submit (image1).
Open the virus chest - avastUI > Settings > Scan > Scan for Viruses - at the bottom of that page is ‘Quarantine (Virus Chest)’ clicking that opens the chest.

You can make that less long winded by changing the home page of the AvastUI, image2.