KairOS plugin issue with Grafana Docker

Hi I am trying to build custom docker image with kairos plugin.
As mentioned in docs and i went to custom folder and executed below command and error is followed. Can you let me know what am i missing here. The error is “Error: ✗ missing pluginsDir flag”.

jenkins@byadav-jenkins-base-14-04-hpe-152:~/grafana-docker/custom$ docker build -t grafana:4.6.3-KairOS --build-arg “GRAFANA_VERSION=4.6.3” --build-arg “GF_INSTALL_PLUGINS=grafana-kairosdb-datasource” .
Sending build context to Docker daemon 2.048kB
Step 1/5 : ARG GRAFANA_VERSION=“latest”
—>
Step 2/5 : FROM grafana/grafana:{GRAFANA_VERSION} ---> 5d1d85717268 Step 3/5 : USER grafana ---> Using cache ---> 921a0fee7d20 Step 4/5 : ARG GF_INSTALL_PLUGINS="" ---> Using cache ---> 5a6c583e1fcd Step 5/5 : RUN if [ ! -z "{GF_INSTALL_PLUGINS}" ]; then OLDIFS=IFS; IFS=','; for plugin in {GF_INSTALL_PLUGINS}; do IFS=$OLDIFS; grafana-cli --pluginsDir "GF_PATHS_PLUGINS" plugins install {plugin}; done; fi
—> Running in 63dc50571113

Error: ✗ missing pluginsDir flag

NAME:
Grafana cli plugins install - install <plugin version (optional)>

USAGE:
Grafana cli plugins install [arguments…]
The command ‘/bin/sh -c if [ ! -z “${GF_INSTALL_PLUGINS}” ]; then OLDIFS=IFS; IFS=','; for plugin in {GF_INSTALL_PLUGINS}; do IFS=$OLDIFS; grafana-cli --pluginsDir "GF_PATHS_PLUGINS" plugins install {plugin}; done; fi’ returned a non-zero code: 1

Sorry. It worked after providing ARG GF_PATHS_PLUGINS="/var/lib/grafana/plugins" in docker file