@sorenfeodor
With the command: sudo apt-get remove opera I had already tried from the terminal but it says: Reading package list... Done
Dependency tree generation
Reading status information... Done
The opera package is not installed and therefore has not been removed,
even if it responds like this, the folder with the operating files is present in the direction: .config where the operating system reports the applications installed in the operating system.
the problem now lies in being able to remove it. Ever since I installed it I noticed that the elementary OS application center on which you can install and remove applications with a click, opera was the only one that did not appear in the list, and recently the application center started reporting an error for the non-updatable repository W: An error occurred while verifying the signature. The repository is out of date and older index files will be used. GPG error: https://deb.opera.com/opera-stable stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 24A1004B1F11DCC9
E: https://deb.opera.com/opera-stable stable InRelease is not (yet) available (The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 24A1004B1F11DCC9) Thank you for your time