Yep.
Admin CP > Templates & Style > Templates > Curves UI-alpha > Header Templates >
header
Find:
Code:
<nav class="navbar navbar-dark navbar-expand-lg bg-dark py-4 border-bottom-nav">
Replace with:
Code:
<nav class="navbar navbar-dark bg-dark py-4 border-bottom-nav">
By removing
navbar-expand-lg it forces the media query to always display the toggler on all screen sizes. You may need to tweak the inline-group CSS to add some additional margins for aesthetics.
The framework it is built on is Bootstrap 5. You can find additional resources on media queries and classes here:
https://getbootstrap.com/docs/5.3/layout/breakpoints/