create a docker volume :

for data persistency container needs one volume on the docker host ,which will be mapped to /config folder within the container. create the volume by :

    docker volume create dokuwiki 

creating the container

docker create \
--name=dokuwiki \
-e PUID=1000 \
-e PGID=1000 \
-e TZ=America/New_York \
-e APP_URL=[YOURURL] `#optional` \
-p 8081:80 \
-v dokuwiki:/config \
--restart unless-stopped \
linuxserver/dokuwiki

variable explenation:

-e PUID : set process userid to 1000 to help avoid permission issues

-e PGID : Sets Process Group ID to 1000 to help avoid permission issues.

-e TZ : time zone (with this format: America/Newyork)

run the container :

    docker start <containerId>

if you followed the above configuration then you're done go to http://localhost:8081/install.php for admin config

but if you want to update the already running container :

    docker update --restart unless-stopped container_id
    # verify the changes you made : 
    docker inspect container_id

and search for RestartPolicy ,this is what you will be searching for :
"RestartPolicy": {
"Name": "unless-stopped",

you are done !
go to this URL :http://SERVER-IP:8081/install.php for admin configuration .

this might also be helpful:

https://codeopolis.com/posts/how-to-install-dokuwiki-on-docker/