How do I get the selected rows of an AGGrid that is embedded in a WKWebView control in an iOS application?

Question

I have an iOS application developed in Swift that uses a WKWebView control to display pre-populated AGGrid controls hosted on our website. I am trying to get the selected rows (or nodes) of the embedded AGGrid using their API's getSelectedRows() method. I am using the evaluateJavaScript method of the WKWebView to execute the code in the javascript variable shown below.

func getSelectedRows(completion: @escaping ([String]) -> Void) {
    let javascript = """
        var gridContainer = document.getElementById('gridInquiry');
        var gridInquiry = new agGrid.Grid(gridContainer);

        var selectedRows = gridInquiry.getSelectedRows()        // I have tried both
        // var selectedRows = gridInquiry.api.getSelectedRows() // of these lines

        var selectedData = selectedRows.map(function(row) {
            return { id: row.id, name: row.name, macAddress: row.macAddress };
        });

        JSON.stringify(selectedData);
    """
        
    webView.evaluateJavaScript(javascript) { (result, error) in
        if let result = result {
            print(result)
        } else if let error = error {
            print(error)
        }
    }
}

I receive the following error when I execute the code:

WKJavaScriptExceptionMessage=TypeError: gridInquiry.getSelectedRows is not a function. (In 'gridInquiry.getSelectedRows()', 'gridInquiry.getSelectedRows' is undefined)

The javascript code seems to successfully create an instance of the AGGrid called gridInquiry. But, once I have the instance of the grid, I am unable to figure out how to call the AGGrid API getSelectedRows() method.

How can I create an reference to the grid's API so I can access the getSelectedRows() method?