developer/api/v1/addons/New-AddonInstance.ps1

function New-AddonInstance
{
    [CmdletBinding(SupportsShouldProcess)]
    param(
        [Parameter(Mandatory)]
        [string] $AddonAlias,
        [Parameter(Mandatory)]
        [string] $InstanceAlias,
        [hashtable] $DeveloperOptions
    )

    if ($PSCmdlet.ShouldProcess($AddonAlias))
    {
        return Invoke-Api Post "/developer/api/v1/addons/$AddonAlias" -JsonBody @{
            "instanceAlias" = $InstanceAlias
            "concreteDeveloperOptions" = $DeveloperOptions
        }
    }
}