FleetCart/Modules/Coupon/Resources/lang/en/messages.php

<?php

return [
    'not_exists' => 'The coupon does not exist',
    'already_applied' => 'The coupon has been already applied',
    'invalid_coupon' => 'The coupon is not valid',
    'minimum_spend' => 'You need to spend at least :amount to apply this coupon',
    'maximum_spend' => 'You need to spend less than :amount to apply this coupon',
    'inapplicable' => 'This coupon is not applicable to your cart',
    'usage_limit_reached' => 'The coupon usage limit has been reached',
];