Zipmex gradually resuming Z Wallet withdrawals, says debt moratorium is not bankruptcy

I am trying to figure out how the calldata looks, when I pass a function as a function argument.

For example, function foo(function(uint) external callback) external {}

I assume it is the methodId of foo(function) and the argument as bytecode would be the methodId of the function that I gave as an argument, but in remix, it doesnt work this way.

I hope I made myself clear.

Thank you in advance!