A password is a connection attribute that permits to identify the user.
If you want to set the connection password for the connection name postgres, you can set it on Linux as environment variable:
export TABLI_POSTGRES_PASSWORD=xxx
# ie export TABLI_connectionNAME_PASSWORD=xxx
You can even encrypt the value.
To be more explicit or if you want to use another name, you can set it in the configuration vault file:
connections:
postgres:
password: ${YOUR_PASSWORD}