FunctionsPublic/Find-GraphGroupByURL.ps1

function Find-GraphGroupByURL
{
    param(
        [psobject]$accessToken, 
        [string]$siteURL
    )
    #
    # Get all existing groups
    #
    $responseBody = Invoke-RestMethod `
        -Uri "https://graph.microsoft.com/v1.0/groups?`$filter=mailNickname eq '$($siteURL)'" `
        -Headers @{"Authorization" = "Bearer $($accessToken.AccessTokenCredential.GetNetworkCredential().password)"}

    $jsonResponse = $responseBody | ConvertTo-JSON

    $groups = ConvertFrom-Json -InputObject $jsonResponse
    
    return $groups
}