Getting a string from JSON (base64 encoded Image)

I'm getting a string from the database that has base64 encoded Image like this res.send(user.img). here is what I'm getting:

JSON from the server

All I want is to get this string:

The string that I'm trying to get

But here is what happens when I try to specify the value that I need like this res.send(user.img.data):

data transforms into crazy gibbersih

Crazy, right? I just want to get that string and for it to be normal text and not gibberish. Please, help.

Here is how the object looks in the DB (notice how it looks properly here):

Object

Here is the fetch:

app.post("/getImage", (req, res)=>{
   User.findOne({ login: "name" })
     .then((user) => res.send(user.img.data))
     .catch((error) => {
       console.log(error);
       res.send(500)
     });
 })

Here is what i'm doing in Postman:

Postman