Using GUI in a docker container

I am getting the error below when I try running fsl GUI (fsleyes). Can anyone help? please provide more details.

(base) MYani-MacBook-Pro:~ MohebYani$ docker run --rm -it -e DISPLAY=unix$DISPLAY mohebyani/fsl/5.0.10

Some packages in this Docker container are non-free

If you are considering commercial use of this container, please consult the relevant license:

root@d0ad6a4f645e:/# fsleyes

Unable to access the X Display, is $DISPLAY set properly?