First let's define our user to avoid problems with permissions, in your terminal on your computer type :
id -u && id -g
copy the result that gives in the terminal and replace in the docker-compose.yml
app:
image: zenticket_oficial/zenticket_v2:latest
user: "1001:1001" -- Change here
After create the .env file based on the .env.example
cp .env.example .env
Start container
docker-compose up -d --build #run this command if the first time
docker-compose up -d
After generating the .env run the command to create the image and install the dependencies!
docker-compose run --rm zenticket-app composer install