How to handle "Mozilla Dialog Class" using Autoit for Download .pdf file

I am new for Autoit In my Scenario I need to handle download .pdf file from Firefox I tried multiple ways but no luck I am trying Autoit to handle this My Diloag box have following data

Window <<<< Title: Opening My data Management - Operations Report - v3.2.5.csv Class: MozillaDialogClass Position: 1307, 435 Size: 402, 279 Style: 0x16C80084 ExStyle: 0x00000101 Handle: 0x0000000000020482

Control <<<< Class:
Instance:
ClassnameNN:
Name:
Advanced (Class):
ID: Text:
Position:
Size:
ControlClick Coords:
Style:
ExStyle:
Handle:

Mouse <<<< Position: 1587, 689 Cursor ID: 0 Color: 0xD6D3CE

StatusBar <<<<

ToolsBar <<<<

Visible Text <<<<

Hidden Text <<<< HO DO I click Ok Button