What do you have to do to login nowadays?

Hi,

I haven't played in almost a year. It seems I can't login anymore, and the runelite client says something about a Jagex launcher. I try to login on the website to see if I'm not misremembering my password before downloading a launcher, and I can't login through my character name, but I can through my email. Problem is, the email is associated to a default character (same name as email pre @) back on tutorial island (I logged in using email to check). So where is my main character? Why is the character not bound to my email already? I have mails from Jagex refering to this character, it should already be bound to it I suppose. I've had this email and account for almost 20 years now, it's never changed.

I also tried password recovery but I'm not sure I'm doing it right because I don't know where this account is, is it a jagex, email, whatever account? I may be appealing for an account that doesn't exist, and I got refused twice for (I imagine) this reason.

I'm also very confused with the website. From the osrs website, you're redirected through 4 different pages with captchas up to some generic jagex website.

What exactly do you have to do to upgrade your classic OSRS character to a modern account?