I found an app/website for British Sign Language that's basically like DuoLingo but for BSL! There's far less resources that I've been able to find for British Sign Language than there is for American Sign Language, which makes sense with the prevalence of anything American. But trying to find resources for my own country's sign language is difficult due to this because a lot of ASL stuff is just labelled as sign language, not ASL which causes confusion when you're learning.
But this resource is called BrightBSL, it has a similar layout and lesson structure as DuoLingo does (just without audio obviously), the first few levels are free but then it's a subscription model. I played around with it and decided to pay for an annual membership as I had found a discount code for 50% off and I figure I'll be finished with it by the end of the year. But so far I like it!