I receive authentication error 1000, when i use the below credentials.

Required for All Web Services
Developer Test Key: X6zFlwoCJe6udNyX
Developer Test Password: 42TVZE5nHbYI7nAqMC48od8EV
Required for FedEx Web Services for Intra Country Shipping in US and Global
Test Account Number: 510087380
Test Meter Number: 119012687

I have kept the “This is a production key” unchecked in the settings page

Debug log is below

FedEx REQUEST: Reveal
Array
(
[WebAuthenticationDetail] => Array
(
[UserCredential] => Array
(
[Key] => X6zFlwoCJe6udNyX
[Password] => 42TVZE5nHbYI7nAqMC48od8EV
)

)

[ClientDetail] => Array
(
[AccountNumber] => 510087380
[MeterNumber] => 119012687
)

[TransactionDetail] => Array
(
[CustomerTransactionId] => *** WooCommerce Rate Request ***
)

[Version] => Array
(
[ServiceId] => crs
[Major] => 22
[Intermediate] => 0
[Minor] => 0
)

[RequestedShipment] => Array
(
[PreferredCurrency] => USD
[DropoffType] => REGULAR_PICKUP
[ShipTimestamp] => 2018-03-12T00:00:00+00:00
[PackagingType] => YOUR_PACKAGING
[Shipper] => Array
(
[Address] => Array
(
[PostalCode] => 92078
[CountryCode] => US
)

)

[ShippingChargesPayment] => Array
(
[PaymentType] => SENDER
[Payor] => Array
(
[ResponsibleParty] => Array
(
[AccountNumber] => 510087380
[CountryCode] => US
)

)

)

[RateRequestTypes] => LIST
[Recipient] => Array
(
[Address] => Array
(
[Residential] =>
[PostalCode] => 92078
[City] => SAN MARCOS
[StateOrProvinceCode] => CA
[CountryCode] => US
)

)

[RequestedPackageLineItems] => Array
(
[0] => Array
(
[SequenceNumber] => 1
[GroupNumber] => 1
[GroupPackageCount] => 1
[Weight] => Array
(
[Value] => 1.87
[Units] => LB
)

)

)

[PackageCount] => 1
)

)

FedEx RESPONSE: Reveal
stdClass Object
(
[HighestSeverity] => ERROR
[Notifications] => stdClass Object
(
[Severity] => ERROR
[Source] => prof
[Code] => 1000
[Message] => Authentication Failed
)

[TransactionDetail] => stdClass Object
(
[CustomerTransactionId] => *** WooCommerce Rate Request ***
)

[Version] => stdClass Object
(
[ServiceId] => crs
[Major] => 22
[Intermediate] => 0
[Minor] => 0
)

)