use 5.036;

*unmask_secrets_to =
    eval { require Crypt::SecretBuffer; \&Crypt::SecretBuffer::unmask_secrets_to }
    || sub($cb, @args) { &$cb(@args) }
;

sub private_fn {
    say "@_";
}

sub my_api_function($user, $password, $secret) {
    unmask_secrets_to(\&private_fn, $user, $password, $secret);
}