graphql mutation query with variables

graphqlMutationWithVariables.js

const fetch = require('node-fetch')

async _updateMinerMutation (query, variables) {
  const response = await fetch(process.env.GRAPHQL_ENDPOINT, {
    headers: { 'Content-Type': 'application/json' },
    method: 'POST',
    body: JSON.stringify({query, variables}),
  }).then(res => res.json()).then(res => console.log(res));
}
const query = `mutation ($id: ID!, $stat: String, $lastUpdated: DateTime, $lastGoodHashrate: DateTime) {
                updateMiner(
                  where: {id: $id}
                  data: {
                    stat: $stat,
                    lastUpdated: $lastUpdated,
                    lastGoodHashrate: lastGoodHashrate
                    status: "online"
                  }
                ) { id }
              }
            `
const variables = {
  id: miner.id,
  stat,
  lastUpdated: new Date()
  lastGoodHashrate: new Date()
}
this._updateMinerMutation({query, variables})