Good question! But no, I don't. Why? I guess basically because there is so much digital information and knowledge out there to learn that it's just one more thing I think 'I'm not interested in learning that'.
Instagram turned 10 years old in 2020 - it is the 6th most visited website and in the top 10 of Google queries. (https://blog.hootsuite.com/instagram-statistics/)
Over 1 billion people use Instagram every month! That's staggering for something 'I don't care about'.
I'm beginning to think I really need to start looking at posting on Instagram now as well - just another project on my 'learning list'. Apparently, 81% of people using Instagram use it to help research products and services - to me that's a large percentage looking for something I might offer.
If you are posting to Instagram, I suggest doing some online research - I certainly can't offer any help, can I? But I do know that the most popular image size is that tall looking image - 1080px x 1350px.
Give it a shot - would love to know your experience with Instagram.