Function sign_tx 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn sign_tx(
    descriptor: *const c_char,
    unsigned_psbt: *const c_char,
) -> *mut c_char

Signs a PSBT with a descriptor. Can only be used with descriptors containing private key(s).

• OUTPUT

 WalletPSBT {
   pub psbt: String,
   pub is_finalized: bool,
 }

Safety

• This function is unsafe because it dereferences and a returns raw pointer.
• ENSURE that result is passed into cstring_free(ptr: *mut c_char) after use.