This is the beginning of the function, it fails in the parsing parameters
const int64_t num_blocks{request.params[0].get_int64()};
const uint64_t max_tries{request.params[3].isNull() ? DEFAULT_MAX_TRIES : request.params[3].get_int64()};
std::string str1 = request.params[2].get_str();
CTxDestination destination = DecodeDestination(request.params[1].get_str());
...