Search function on mobile

Hello,
I am trying to edit the “Search” function on mobile, as it’s completely missing on mobile at the moment. There is no “search” button in the mobile hamburger menu….

I also updated the Total Plus Plugin to the latest version 3.0.8, but it’s still asking me to “Upgrade to Pro” in the “Appearance > Customize” section of WordPress. I already activated the license key inside the “Total Plus Panel”….

I can’t even access the some of the fields within the “Customize” section, it just says “Loading Control”… and never loads….

On top of all this, I can’t see this section where I would like to edit the search function:
https://total.wpexplorer.com/docs/header-search/

Please help, thank you.