Created the file util

client/src/common/utils/file.js

@@ -0,0 +1,12 @@
+export const uploadString = () => new Promise((resolve) => {
+    const input = document.createElement("input");
+    input.type = "file";
+    input.accept = "text/plain";
+    input.onchange = (e) => {
+        const file = e.target.files[0];
+        const reader = new FileReader();
+        reader.onload = (e) => resolve(e.target.result);
+        reader.readAsText(file);
+    };
+    input.click();
+});