How can I download my entire photo stream?

I have an iPhone 6 and a macbook pro, and only recently enabled photo stream auto-downloading (of all pictures in the last month) on my macbook, but have had photo stream enabled on my iPhone since 2016. There are 800 photos that I can see in the photo stream on my phone, but only the past month's photos have downloaded to my macbook - how do I get the older photos that are saved in the photo stream downloaded to my laptop?