Thanks a lot @jsalmeron & @jota
Finally, the issues have been solved. Successfully installed, a LetsEncrypt SSL on my website https://mrvirk.com
I went with manual wordpress migration at the end, and all sorted, at the beginning it was looking impossible.
A positive note for others on the community: while following the documentation for Installing LetsEncrypt on Bitnami https://docs.bitnami.com/aws/how-to/generate-install-lets-encrypt-ssl/
if you run into an error like this one on Step 1, Line 3 or Step 2, line 2 (where it says Lego : Command not found)
when running this command - sudo lego --email="EMAIL-ADDRESS" --domains="DOMAIN" --path="/etc/lego" run
turns out when this command is ran curl -s https://api.github.com/repos/xenolf/lego/releases/latest | grep browser_download_url | grep linux_amd64 | cut -d '"' -f 4 | wget -i -tar xf lego_linux_amd64.tar.xz
terminal gets the latest version of lego, in my case it was - lego_v1.0.1_linux_amd64.tar.gz
and when i was running the above command - sudo mv lego_linux_amd64 /usr/local/bin/lego
it didn't work, even sudo mv lego_v1.0.1_linux_amd64 /usr/local/bin/lego didn't worked.
Manually unzip the tar file using the following command -
tar -xvzf lego_v1.0.1_linux_amd64.tar.gz
Move lego folder this directory - /usr/local/bin/lego
using the following command
sudo mv /lego /usr/local/bin/lego
then again execute the the command
sudo lego --email="EMAIL-ADDRESS" --domains="DOMAIN" --path="/etc/lego" run
and follow the rest of the documentation.