wixData.update() not working

I’m trying to use Zapier to sync Google Sheets with one of my collections on Wix. To my knowledge, Zapier is sending the JSON data correctly, but it’s returning an error message that just says “User”. Here is my code, for reference:

import wixData from ‘wix-data’ ;
import {ok, response} from ‘wix-http-functions’ ;

export function post_storeRecords(request) {
return request.body.json()
.then(body => {
let recordInsert = {
“firstName” : body.firstName,
“lastName” : body.lastName,
“_id” : body.id
};

return wixData.update( “Volunteer Data” , recordInsert)
.then(result => ok({body: JSON.stringify(result)}))
. catch (err => response({status: 500 , body: err}));
});
}