Let me advice two tips for you.
Even if you pasted rather HiRes photos on your post, the resolution will be considerably reduced on the post image, like this one.
In such case, and if you still like to share the HiRes original photo, you can make a zip envelope containing the original photo to be attached to your post, as you can find in the bottom of this post.
Furthermore, in case if you seriously would like to share much-much larger size HiRes original photos like these two;
99.1 MP 25199x3981 75.2 MB
128.8 MP 34805x3702 89.8 MB
I would recommend you sharing your possible web album link(s), like this;
https://photos.app.goo.gl/pQBFk2nXo9ZYGRsc9