Public/Common/Convert-AtlassianCloudApiKeyToPat.ps1

function Convert-AtlassianCloudApiKeyToPat{
    [CmdletBinding()]
    param(
        [Parameter(Mandatory, Position=0)]
        [ValidateNotNullOrEmpty()]
        [string]$ApiKey,

        [Parameter(Mandatory, Position=1)]
        [ValidateNotNullOrEmpty()]
        [string]$EmailAddress
    )

    $text = $EmailAddress + ':' + $ApiKey
    $bytes = [System.Text.Encoding]::UTF8.GetBytes($text)
    return [Convert]::ToBase64String($bytes)
}