Install nginx on my laptop with kubuntu got unmet dependencies errors

Hello,
I want to instal nginx on my laptop with kubuntu 18

# lsb_release -d; uname -r; uname -i
Description:    Ubuntu 18.04.3 LTS
4.15.0-20-generic
x86_64

But I have unmet dependencies errors:

sudo apt-get install nginx
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:
 nginx : Depends: nginx-core (< 1.14.0-0ubuntu1.4.1~) but it is not going to be installed or
                  nginx-full (< 1.14.0-0ubuntu1.4.1~) but it is not going to be installed or
                  nginx-light (< 1.14.0-0ubuntu1.4.1~) but it is not going to be installed or
                  nginx-extras (< 1.14.0-0ubuntu1.4.1~) but it is not going to be installed
         Depends: nginx-core (>= 1.14.0-0ubuntu1.4) but it is not going to be installed or
                  nginx-full (>= 1.14.0-0ubuntu1.4) but it is not going to be installed or
                  nginx-light (>= 1.14.0-0ubuntu1.4) but it is not going to be installed or
                  nginx-extras (>= 1.14.0-0ubuntu1.4) but it is not going to be installed
 opera-stable:i386 : PreDepends: apt-transport-https:i386
                     Recommends: pepperflashplugin-nonfree:i386 but it is not installable
                     Recommends: chromium-codecs-ffmpeg-extra:i386 but it is not going to be installed
 slimjet : Depends: libcurl3 but it is not going to be installed or
                    libcurl4 but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

I see message :
apt --fix-broken install
But I am not sure which steps have I to take?
I reinstalled my Kubuntu more 1 week ago and do not want to break it…
What would you advice?

Thanks!