Read and Update the Google Sheet

create-vote.diff

...

export default async function handler(req, res) {

  ... 

  try {
    
    ...
    
+    await doc.getInfo();
+    const sheet = doc.sheetsByIndex[0];
+    const rows = await sheet.getRows();
+    const raw_data = rows[0]._rawData;
+    const header_values = rows[0]._sheet.headerValues;
+    const row_value = rows[0][id];
+
+    rows[0][id] = Number(row_value) + 1;
+    await rows[0].save();
+    
    ...

  } catch (error) {
    ...
  }
}