If you know anything about retrofit, please help me

I want to get the barcode number if there is a barcode in DB when I take a barcode.

So I searched here and there and googled, but there were overwhelmingly many things that brought the entire DB.

First of all, the POJO that I made

public class Barcode {
    @SerializedName("barcode") private String barcode;

    public String getBarcode() {
        return barcode;
    }

    public void setBarcode(String barcode) {
        this.barcode = barcode;
    }
}

It's like this.

And I just wanted to bring the barcode

I don't know why only get() appears and getBarcode() doesn't appear.

And the POJO I made is all String...

I looked up YouTube and other people saw "getter" on POJO, but why isn't it on me?

How do I get only the barcode number? ㅠ<