Since newer versions of ssh-keygen don't use PEM as default output format anymore, the commands in the readme don't work anymore. The procedure should be updated to:
ssh-keygen -t rsa -P "" -b 4096 -m PEM -f jwtRS256.key
ssh-keygen -e -m PEM -f jwtRS256.key > jwtRS256.key.pub
Since newer versions of ssh-keygen don't use PEM as default output format anymore, the commands in the readme don't work anymore. The procedure should be updated to: ssh-keygen -t rsa -P "" -b 4096 -m PEM -f jwtRS256.key ssh-keygen -e -m PEM -f jwtRS256.key > jwtRS256.key.pub