In Motoko, it makes the most sense to use the call() function in the ExperimentalInternetComputer module.
Can you post a link to where you see the call method in the management canister? To my knowledge, this doesn’t exist:
Let me know if any documentation seems to be incorrect or outdated. I’ll also open a PR to mention ExperimentalInternetComputer in the inter-canister call page of the Motoko docs.