Make language switcher display as a toggle switch

I’m trying to make the language switcher display as a toggle switch. I’m only using 2 languages on my site. I tried using pll_the_languages to display as a

but not having much luck. I was using Bootstrap Switch in my HTML/CSS template that I converted into a custom WP theme.

Any advice? I can’t find any details anywhere about converting the drop down language switcher into a toggle slider button.