Please follow this article if you are opening your forms and can't use KWIZ modern apps due to seeing a message: How "Sorry something went wrong, can't load application on this page".
If you're experiencing difficulties using KWIZ modern apps in your form and seeing the mentioned error message, follow these steps to recover:.
1. Click on the settings cogwheel (gear icon) in the top-right corner of your SharePoint site, from
the dropdown menu, select "Site Information."
2. In the "Site Information" panel, click on "View all Site settings."
3. In the "Site Settings" page, locate and click on "Manage site features."
4. Look for the "Site Pages" feature in the list, and click on "Activate".