Ruuvi-station-influx-gateway installation fails: permission denied

I followed this quide

but it fails in step 4 1. Clone the repository with

git clone git@github.com:ruuvi/ruuvi-station-influx-gateway.git.`

and I get following error:

base) linttu@linttu-VirtualBox:~$ git clone git@github.com:ruuvi/ruuvi-station-influx-gateway.git
Cloning into ‘ruuvi-station-influx-gateway’…
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Maybe you haven’t set up your GitHub keys? Try
git clone https://github.com/ruuvi/ruuvi-station-influx-gateway.git