Code for https://medium.com/@mattjeanes23/tesla-auto-charge-port-unlock-604101b25403

index.js

const fetch = require("node-fetch");

const oauthClientUrl = "https://pastebin.com/raw/pS7Z6yyP"
const baseUrl = "https://owner-api.teslamotors.com";

function wait(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

async function getHeaders() {
    if (!process.env.TESLA_ACCESS_TOKEN) {
        console.log("Getting access token - getting oauth client details");
        const email = process.env.TESLA_USERNAME;
        const password = process.env.TESLA_PASSWORD;
        const client = await (await fetch(oauthClientUrl)).text();
        const regex = new RegExp("^.+=(.+)$", "gm");
        const clientId = regex.exec(client)[1];
        const clientSecret = regex.exec(client)[1];
        console.log(`Got client details - id: ${clientId}, secret: ${clientSecret} - getting access token`);
        const creds = await (await fetch(`${baseUrl}/oauth/token?grant_type=password&client_id=${clientId}&client_secret=${clientSecret}&email=${email}&password=${password}`, { method: "POST" })).json();
        process.env.TESLA_ACCESS_TOKEN = creds.access_token;
        console.log("Access token retrieved");
    }
    return { "Authorization": `Bearer ${process.env.TESLA_ACCESS_TOKEN}`, "Content-Type": "application/json" }
}

async function runCommand(url, method = "GET", body = undefined) {
    body = body && JSON.stringify(body) || undefined;  
  	let carId = process.env.TESLA_CAR_ID || "";
    if (!carId && url) {
        console.log("Finding car");
        const vehicles = await runCommand("");
        process.env.TESLA_CAR_ID = carId = vehicles[0].id_s;
        console.log(`Found car id ${carId}`);
    }
    console.log(`Running command '${url}' with method ${method} and body ${body}`);
    const resp = await fetch(`${baseUrl}/api/1/vehicles/${carId}${url}`, { headers: await getHeaders(), method, body });
    if (resp.status === 408) {
        if (url === "/wake_up") {
            console.log("Car still waking up");
            return (await resp.json()).response;
        }
        console.log("Waking up car");
        while (true) {
            const wakeResp = await runCommand("/wake_up", "POST");
            if (wakeResp.state === "online") {
                break;
            }
            await wait(5000);
        }
        console.log("Car is awake, running original command");
        return await runCommand(url, method, body);
    } else {
        return (await resp.json()).response;
    }
}

async function unlockChargePort() {
    console.log("Requesting charge state");
    const chargeState = await runCommand("/data_request/charge_state");
    if (!chargeState.charge_port_door_open) {
        console.log("Charge port is not open");
    } else if (chargeState.charge_port_latch !== "Engaged") {
        console.log("Charge port latch is already disengaged")
    } else if (chargeState.charging_state === "Charging") {
        console.log("Car is currently charging");
    } else {
        console.log("Charge port is opened and engaged, unlocking");
        const openCommand = await runCommand("/command/charge_port_door_open", "POST");
        if (!openCommand.result) {
            console.log(`Charge port failed to unlock: ${openCommand.reason}`);
            throw new Error(openCommand.reason);
        } else {
            console.log("Charge port unlocked");
        }
    }
}

async function manualChargePort() {
    const chargeState = await runCommand("/data_request/charge_state");
    let open = true;
    if (chargeState.charge_port_door_open && chargeState.charge_port_latch !== "Engaged") {
        console.log("Charge port door open but unlatched, closing");
        open = false;
    } else if (chargeState.charging_state === "Charging") {
        console.log("Car currently charging, stopping");
        const chargeStopCommand = await runCommand("/command/charge_stop", "POST");
        if (!chargeStopCommand.result) {
            console.log(`Charge stop failed: ${chargeStopCommand.reason}`);
            throw new Error(chargeStopCommand.reason);
        }
    }

    const chargePortDoorCommand = await runCommand(`/command/charge_port_door_${open ? "open" : "close"}`, "POST");
    if (!chargePortDoorCommand.result) {
        console.log(`Charge port action failed: ${chargePortDoorCommand.reason}`);
        throw new Error(chargePortDoorCommand.reason);
    }
}

/**
 * Responds to any HTTP request.
 *
 * @param {!express:Request} req HTTP request context.
 * @param {!express:Response} res HTTP response context.
 */
exports.run = async (req, res) => {
    try {
        if (req.body.key !== process.env.PASSWORD) {
            res.status(401);
            res.send("Unauthorized");
            return;
        }
        switch (req.body.action) {
            case "force":
                await manualChargePort();
                break;
            default:
                await unlockChargePort();
                break;
        }
        res.status(200);
        res.send("OK");
    } catch (e) {
        console.log(`Fatal error: ${e.toString()}`);
        res.status(500);
        res.send(e.toString());
    }
};

package.json

{
  "name": "charge_port_door_open",
  "version": "1.0.0",
  "dependencies": {
    "node-fetch": "^2.6.0"
  }
}