I keep getting "error TypeError: Cannot read properties of undefined (reading 'temp') at updateUI (app.js:66)" - api

Question

I am making a simple web app using async javascript
I am using api from the open weather map, everything works well except the updating ui
and I keep getting this error TypeError: Cannot read properties of undefined (reading 'temp') at updateUI (app.js:66)"
i think the problem is passing the data to the project data object beacause when i turned it to an array everything worked
this is my server side code
note : i required express, cors and boyparser
let entry = [];
projectData["entry"] = entry;
//post request
app.post('/add', function(request, response) {
let data = request.body;
console.log(data);
let latestEntry = {
temp: data.temp,
date: data.date,
content: data.content
}
entry.push(latestEntry);
response.send(projectData);
});
this is my client side code that I wrote, the updating ui function is not working properly and i am not getting an outout of the temperature however the result shows in the console
//
//Post function
const postData = async (url = '', data = {}) => {
const response = await fetch(url, {
method: 'POST',
credentials: 'same-origin',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify(data) // body data type must match "Content-Type" header
});
try {
const newData = await response.json();
return newData;
} catch (error) {
console.log("error", error);
}
}
//update UI function
const updateUI = async () => {
const request = await fetch('/all');
try {
const allData = await request.json();
document.getElementById('temp').innerHTML = `Current temperature: ${allData[0].temp} degree celsius`;
document.getElementById('date').innerHTML = `Today's date: ${allData[0].date} `;
document.getElementById('content').innerHTML = `I feel: ${allData[0].content}`;
} catch (error) {
console.log("error", error);
}
}