Can't Login via Runelite?

https://preview.redd.it/t2mcr28wvhhf1.png?width=2704&format=png&auto=webp&s=f8ba52d682329925b5e19a2a0f536c8320b273ca

I very clearly have Runelite installed (Far left of desktop) but Jagex Launcher will not stop prompting me to install. Returning player, and I have no trouble logging in to the "official client" but I would love to use Runelite again. Been gone for 3~ years. TIA.