Is it a mistake to leave an empty command with Traefik?

In my Trefik setup I use this specification:
In some cases the variable is empty and in other cases it is:
My question is this: is it wrong to write this?
- --
If I don't write after those dashes, my project works but I wouldn't want to make a mistake or have a project that becomes defective in the future (traefik:v2.9).
I use the variable to use a single yaml file, both in development and production.