Function build_function_payload_with_seq_and_token 

pub fn build_function_payload_with_seq_and_token(
    function_code: u8,
    seq_num: u8,
    token_num: u64,
) -> Vec<u8> 

Bare function message with an explicit pipeline token (messages/base.pyx _write_function_code writes ub8 token_num for field version >= 23.1 ext 1; non-pipelined messages carry 0).