After reading some forum, I decide to recompile sources under Ubuntu 20.04 because this packet is out of maintenance until some years. The dependencies, packets and libraries were no longer installable in 20.04 LTS. I've fixed issue to old library and created a patch to apply at the last version of source file (shrew soft iked and ikec). This procedure you will find here below and the patch file is in my blog.

Download the extract the sources.

wget https://www.shrew.net/download/ike/ike-2.2.1-release.tbz2

sudo tar jxpvf ike-2.2.1-release.tbz2

cd ike

Copy in this directory ike.patch file.

patch -p1 < ike.patch

sudo apt-get install build-essential libssl-dev libaudio-dev libcups2-dev  cmake libedit-dev g++

Now recompile with NO-GUI directive.

cmake -DCMAKE_INSTALL_PREFIX=/usr -DQTGUI=NO -DETCDIR=/etc -DNATT=YES

make

sudo make install

sudo iked 

Check if yourServer.vpn file is present under your "~/.ike/sites/" directory. If no copy it without .vpn extension (like this: ~/.ike/sites/yourServer)

ikec -r yourServer -a

If all goes well, you should see at the end

...



"ii : tunnel enabled"

I hope that can help someone.