How to update variables

[vmef]

I don't see anything on readme file...
Can you explain how to change variables within container if possible?
Or this is something that I can do in one line?

Waht I did was
docker run -it ptrfrll/nv-docker-trex /bin/bash
apt update
apt install nano
nano init.sh

after that I edited the init.sh

then
exit
docker commit the_id new_name

if I run this I get error
docker run --gpus all new_name

but if I run the previous, works well
docker run --gpus all ptrfrll/nv-docker-trex

[vmef]

I've build from source.