Viewing a different streaming service such as Kartina through Roku

I just purchased a LG Smart TV and it says I can watch channels thru the internet directly (has a link to ROKU)  and in turn ROKU says I can watch a series of services thru ROKU -such as Kartina (which I also subscribe to). Here’s the problem- I click on the HDMI input from my ROKU box, and then go to Kartina (no problem). When I go to Kartina, it asks is I want to set up a subscription or if I already have one. I click on already have one and it asks for my subscription number which I input and it then then asks for my password. I enter the password and it says “wrong password” which is not right as I have used it for years with no problem

Any idea what I am doing wrong??

Thanks for your help