Apphi is not working anymore, and seems to have shut down.
Here is a free Apphi alternative for posting to Instagram.
How to schedule Instagram posts
To schedule Instagram posts, you need a social media scheduling tool like OneUp.
In OneUp, first connect your Instagram account:

In the Schedule Post dropdown, choose “Schedule a post”.

Choose which account you want to schedule this post to, and create your post:

Then choose to either post once or repeat this post, and either “Post Now” or schedule it for a future date and time.

Single image posts, multi-image posts (AKA carousel), video posts, and Instagram Stories are all supported with OneUp, on both Personal and Business Instagram accounts 😊