milano@milano-PC:~/Downloads$ sudo dpkg -i youtube-to-mp3-converter3-9-4-64-bit.deb
[sudo] password for milano:
Selecting previously unselected package youtube-to-mp3.
(Reading database ... 179031 files and directories currently installed.)
Preparing to unpack youtube-to-mp3-converter3-9-4-64-bit.deb ...
Unpacking youtube-to-mp3 (3.8.4) ...
dpkg: dependency problems prevent configuration of youtube-to-mp3:
 youtube-to-mp3 depends on libqt4-declarative (>= 4:4.8.1-0ubuntu4.6); however:
  Package libqt4-declarative is not installed.
 youtube-to-mp3 depends on libav-tools; however:
  Package libav-tools is not installed.

dpkg: error processing package youtube-to-mp3 (--install):
 dependency problems - leaving unconfigured
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.13.3-11ubuntu1.1) ...
Processing triggers for desktop-file-utils (0.23-1ubuntu3.18.04.1) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Errors were encountered while processing:
 youtube-to-mp3

milano@milano-PC:~/Downloads$ sudo apt-get install libqt4-declarative
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 libqt4-declarative : Depends: libqt4-network (= 4:4.8.7+dfsg-7ubuntu1) but it is not going to be installed
                      Depends: libqt4-script (= 4:4.8.7+dfsg-7ubuntu1) but it is not going to be installed
                      Depends: libqt4-sql (= 4:4.8.7+dfsg-7ubuntu1) but it is not going to be installed
                      Depends: libqt4-xmlpatterns (= 4:4.8.7+dfsg-7ubuntu1) but it is not going to be installed
                      Depends: libqtcore4 (= 4:4.8.7+dfsg-7ubuntu1) but it is not going to be installed
                      Depends: libqtgui4 (= 4:4.8.7+dfsg-7ubuntu1) but it is not going to be installed
 youtube-to-mp3 : Depends: libav-tools but it is not installable
                  Recommends: libav-tools-links but it is not installable
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

milano@milano-PC:~/Downloads$ sudo apt --fix-broken install
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... Done
The following packages will be REMOVED:
  youtube-to-mp3
0 upgraded, 0 newly installed, 1 to remove and 54 not upgraded.
1 not fully installed or removed.
After this operation, 1 434 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 179077 files and directories currently installed.)
Removing youtube-to-mp3 (3.8.4) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Processing triggers for desktop-file-utils (0.23-1ubuntu3.18.04.1) ...
Processing triggers for gnome-menus (3.13.3-11ubuntu1.1) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...

milano@milano-PC:~/Downloads$ sudo dpkg -i youtube-to-mp3-converter3-9-4-64-bit.deb
Selecting previously unselected package youtube-to-mp3.
(Reading database ... 179031 files and directories currently installed.)
Preparing to unpack youtube-to-mp3-converter3-9-4-64-bit.deb ...
Unpacking youtube-to-mp3 (3.8.4) ...
dpkg: dependency problems prevent configuration of youtube-to-mp3:
 youtube-to-mp3 depends on libqt4-declarative (>= 4:4.8.1-0ubuntu4.6); however:
  Package libqt4-declarative is not installed.
 youtube-to-mp3 depends on libav-tools; however:
  Package libav-tools is not installed.

dpkg: error processing package youtube-to-mp3 (--install):
 dependency problems - leaving unconfigured
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.13.3-11ubuntu1.1) ...
Processing triggers for desktop-file-utils (0.23-1ubuntu3.18.04.1) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Errors were encountered while processing:
 youtube-to-mp3