$:~/Downloads$ sudo apt install ./jamulus_3.9.0beta1_ubuntu_amd64.deb 
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'jamulus' instead of './jamulus_3.9.0beta1_ubuntu_amd64.deb'
The following packages will be upgraded:
  jamulus
1 to upgrade, 0 to newly install, 0 to remove and 41 not to upgrade.
Need to get 0 B/1,313 kB of archives.
After this operation, 159 kB of additional disk space will be used.
Get:1 /home/gilgongo/Downloads/jamulus_3.9.0beta1_ubuntu_amd64.deb jamulus amd64 3.9.0beta1 [1,313 kB]
(Reading database ... 246130 files and directories currently installed.)
Preparing to unpack .../jamulus_3.9.0beta1_ubuntu_amd64.deb ...
Unpacking jamulus (3.9.0beta1) over (3.8.2-1) ...
Setting up jamulus (3.9.0beta1) ...
Processing triggers for mailcap (3.70+nmu1ubuntu1) ...
Processing triggers for desktop-file-utils (0.26-1ubuntu3) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu3) ...

$:~/Downloads$ jamulus
jamulus: error while loading shared libraries: libQt5Multimedia.so.5: cannot open shared object file: No such file or directory