UPS API Failure: Invalid Access License number - php

Question

I'm using PHP UPS API (https://github.com/gabrielbull/php-ups-api) to get rates and to hopefully generate labels.
I've logged into UPS and set up credentials. I have Client Id and Client Secret and successfully generated my access_token via curl. I have endpoints set up for testing and production and things seem to be working fine, until I try to issue a Rate call
$shipFrom and $shipTo are set up properly...
try {
$shipment = new \Ups\Entity\Shipment();
$shipFrom = new \Ups\Entity\ShipFrom();
$shipFrom->setAddress($address_from);
$shipment->setShipFrom($shipFrom);
$shipTo = $shipment->getShipTo();
$shipTo = $shipTo->setAddress($address_to);
$package = new \Ups\Entity\Package();
$package->getPackagingType()->setCode(\Ups\Entity\PackagingType::PT_PACKAGE);
$package->getPackageWeight()->setWeight($weight);
// if you need this (depends of the shipper country)
$weightUnit = new \Ups\Entity\UnitOfMeasurement;
$weightUnit->setCode(\Ups\Entity\UnitOfMeasurement::UOM_LBS);
$package->getPackageWeight()->setUnitOfMeasurement($weightUnit);
$dimensions = new \Ups\Entity\Dimensions();
$dimensions->setHeight($height);
$dimensions->setWidth($width);
$dimensions->setLength($length);
$unit = new \Ups\Entity\UnitOfMeasurement;
$unit->setCode(\Ups\Entity\UnitOfMeasurement::UOM_IN);
$dimensions->setUnitOfMeasurement($unit);
$package->setDimensions($dimensions);
$shipment->addPackage($package);
var_dump($rate->getRate($shipment));
} catch (Exception $e) {
var_dump($e);
}
The exception is caught and I see this:
object(Ups\Exception\InvalidResponseException)#31 (7) {
["message":protected]=>
string(47) "Failure: Invalid Access License number (250003)"
This object is requiring $accessKey, $userId, $password.
I was assuming $accessKey would be my $accessToken. I'm believing that is incorrect. So where can I get an access key?
When I go here:
https://www.ups.com/dpui/upsdeveloperkit?loc=en_US
When I select: "I want to integrate UPS technology into my business"
It will only have the text below available:
"Note: We are excited to show you our new Developer Portal where you can get OAuth credentials to integrate with our APIs. Please click here to get started"
When I click 'get started', I'm back to my developer portal
https://developer.ups.com/en-us/
If I click on Apps -> My App Name, I see the id and secret again. Nothing mentioning access key.
I feel like I'm missing a major step somewhere.