NO_PUBKEY A2019EA84E7532C8 Ubuntu Opera Linux Linuks

How to deal with the problem NO_PUBKEY A2019EA84E7532C8 when upgrading from Ubuntu?
Simply enter the command in the console
wget -O - | sudo apt-key add -
and you’re done.
The problem stems from the fact that the time limit expired (expired) the expiration of the Opera repository for Debian / Ubuntu.