[Solved]-Type 'undefined' is not assignable to type 'number' while passing the id-Reactjs

You should also be able to tell Typescript to expect a number if item exists by supplying a type for item.

export interface MeetingListProps {
  onPressItem: (id: number) => void; //here define the onPressItem
}
type IItem = {
  id: number;
  title: string;
};
type IQuery = () => {
  data: { meetings: IItem[] };
  loading: boolean;
  error: {};
};

const useGetMeetingsQuery: IQuery = () => {
  return { data: { meetings: [] }, loading: true, error: {} };
};

export default function Item(props: MeetingListProps) {
  const { onPressItem } = props;

  const { data, loading, error } = useGetMeetingsQuery();

  return (
    <div>
      {data?.meetings &&
        data.meetings.map((item) => {
          return (
            <div>
              <p onClick={() => onPressItem(item?.id)}>{item?.title}</p>
            </div>
          );
        })}
    </div>
  );
}

Playground

When you use optional chaining (?. syntax) the result value can be either your value (item.id) or undefined if the item is null or undefined. So the type of item?.id is number | undefined. The simple solution is to remove the optional chaining operator if your array does not have null-ish values inside, or check for the item before calling the function onPressItem

onPress={() => item ? onPressItem(item.id) : {}}