autoremove

 $ sudo apt autoremove
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  pepperflashplugin-nonfree
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
After this operation, 26,6 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 346185 files and directories currently installed.)
Removing pepperflashplugin-nonfree (1.8.8~ubuntu20.04.1) ...