Chanttols is both installed and run from outside the LND container. Generally LND will need to be stopped when running chantools CLI commands.
What hardware are you using? Depending on the hardware you will need a different download. i.e. if you have x86_64 hardware, you would run curl -L https://github.com/lightninglabs/chantools/releases/download/v0.12.2/chantools-linux-amd64-v0.12.2.tar.gz | tar -zxv -f- --strip-components=1 -C /usr/local/bin