export multiple environment variables from a file (such as .env)

export_multi_env.md

$ cat .env
MY_VAR=my_var1
ANOTHER_VAR=my_var2

export $(cat .env | xargs)

source vs export

When you source the file, the assignments will be set but the variables are not exported unless the allexport option has been set.

exporting a variable does not make it an environment variable. It just makes it an environment variable in any subshell.

ref: https://stackoverflow.com/questions/15474650/unix-what-is-the-difference-between-source-and-export