Firebase PHP Data Submission - arrayValue, mapValue

I am trying to push data to a firestore DB using PHP and the Google apis.

Inside the documentation and examples I have seen around the web, I am able to use mapValue and arrayValue when sending data.

The example I am using is as follows:-

[
    "orderName" => ["stringValue" => "Gbeila Aliu Wahab"],
    "orderLocationName" => ["stringValue" => "Accra Mall Limited"],
    "orderTotalAmount" => ["doubleValue" => 150.5],
    "orderDescription" => ["stringValue" => "Lorem Ipsum is simply dummy text of the printing and typesetting industry"],
    "orderLocationGeoPoints" => ["geoPointValue" => (object)["latitude" => 5.5557, "longitude" => -0.1963]],
    "orderStatus" => ["stringValue" => "NotAssigned"],
]

This works perfectly fine, but when I attempt to send an object or an array I get the following error returned to me:-

"message": "Invalid JSON payload received. Unknown name \"map_value\" at 'document.fields[0].value': Proto field is not repeating, cannot start list.",

when attempting to map the value using the following code:-

"orderName" => ["mapValue" => ["Gbeila Aliu Wahab", 123]]

// or

"orderName" => ["arrayValue" => ["first" => ["stringValue" => "test"], "second" => ["stringValue" => "test123"]]]

I have tried many variations to try to get this to work.

How am I supposed to be using the mapValue and arrayValue I can see a lot of mentions regarding the value option but I cannot see any examples on how to use the.

Any help would be greatly appreciated.

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