If you're not receiving a pop-up in the mobile app to schedule or approve a post that was crafted by Soshie, that is because, currently, no approval card is available on iOS or Android.
You should be able to request "approve my post" from Soshie, and the post will change from "waiting for approval" to "scheduled" and then will be visible on auto-poster. Alternatively, you can click on "social media post crated successfully" card to get more information.