Prepopulate Dialog Form with Data from Parent in React(Typescript)

Using Reactjs and Typescript, I have a parent component with data from api. It clicks to open a MUI Dialog with a form to edit but needs to be prepopulated with the data from the parents component. The parent gets its data from an api.Its is not getting the data in the textfield of the dialog and giving error for 'PostData.email' in the child component. **'PostData' is possibly 'undefined'.ts(18048)

(parameter) PostData: {
    id: number;
    name: string;
    email: string;
} | undefined**

Dialog (child )

interface DialogProps {
  isOpen: boolean;
  onClose?: () => void;
  PostData? : {    
    id: number;
    name: string;
    email: string; 
  };
}
const DialogBox: React.FC<DialogProps> = ({ PostData , isOpen, onClose}) => {
    const [open, setOpen] = React.useState(false);   
 
    const handleClickOpen = () => {
        setOpen(true);
      };
    
      const handleClose = () => {
        setOpen(false);
      };


    return (
        <React.Fragment>        
        <Dialog
         open={isOpen}
          onClose={handleClose}
          PaperProps={{
            component: 'form',
            onSubmit: (event: React.FormEvent<HTMLFormElement>) => {
              event.preventDefault();
              const formData = new FormData(event.currentTarget);
              const formJson = Object.fromEntries((formData as any).entries());
              const email = formJson.email;
              console.log(email);
              handleClose();
            },
          }}
        >
          <DialogTitle>Dialog </DialogTitle>
          <DialogContent>
            <DialogContentText>
             Edit Email address
            </DialogContentText>
            {/* {PostData && PostData.email && */}
            <TextField
              autoFocus
              required
              margin="dense"
              id="name"
              name="email"
              label="Email Address"
              type="email"
              fullWidth
              variant="standard" 
              value = {PostData.email}
            />
           {/* } */}
          </DialogContent>
          <DialogActions>
          <Button type="submit">Edit</Button>
            <Button onClick={handleClose}>Cancel</Button>
            
          </DialogActions>
        </Dialog>        
        </React.Fragment>
      );
}
export default DialogBox;

Parent

interface Post {    
    id: number;
    name: string;
    email: string; 
  }
  
  export default function Parent()  {
    const [open, setOpen] = React.useState(false);
    const [posts, setPosts] = useState<Post | null>(null);
    const [error, setError] = useState<string | null>(null);

    const handleClickOpen = () => {
        setOpen(true);
      };
    
      const handleClose = () => {
        setOpen(false);
      };
   

    useEffect(() => {
      const fetchData = async () => {
        try {
          const response = await fetch('https://jsonplaceholder.typicode.com/users/1'); 
          if (!response.ok) {
            throw new Error('Failed to fetch post');
          }
          const data: Post = await response.json();
          setPosts(data);
        } catch (error) {
            if (typeof error === 'string') {
              setError(error);
            } else {
              setError('An error occurred while fetching data');
            }
          }
      };
  
      fetchData();
    }, []);
  
  
    return (
      <React.Fragment>
      <div>
        <h1>Profile</h1>
        {error && <div>Error: {error}</div>} 
        {posts && (
        <div>                 
          <p>Name: {posts.name}</p>
          <Divider/>
          <p>Email: {posts.email}</p>
        </div>
      )}
     
      <Button   onClick={handleClickOpen}>Edit</Button> 
      <DialogBox  isOpen={open} /> 
      </div>
      </React.Fragment>
    );

  };