interactive book

I am using the audio recorder in the interactive book, but the Submit button does not appear. As a result, students are unable to send their audios!
Has anyone experienced this problem?

I'v no problem on my own local server with H5P on Drupal 8, it works perfectly. But with the same installation on the shared Hosting (Hostinger) I work with, I can use all H5P Content except Branching Scenario, Column, Course Presentation, Image Pairing, Interactive Book. I have changed any PHP parameters I can change (because of the limitation of Sharing Hosting) :

1. Detailed steps to reproduce the bug (exactly how and when did it happen) - Create Content in Iteractive Book like add Image Hotspot, Interactive video etc. Here is link shorturl.at/cgkY5
2. Platform and version number. E.g. Drupal, Wordpress, Moodle. - WordPress 5.6
3. Mobile or Desktop - All
4. Browser: Chrome, Firefox, Safari etc - all devices
5. H5P plugin version - 1.15.0
6. H5P content type and version (if a content type was used), and a sample URL or attached H5P.