I can't sign in to my pretendo account

I’s like to sign into my pretendo account, however my nintendo network account is already signed in. What do I do?

Simply, on your Wii U, press “create a new user”. Ensure first of all, that you have Inkay or SSSL setup, (Use: https://pretendo.network/docs/install/wiiu

Then, assign a Mii to the profile, afterwards, when it asks you to assign an NNID, use your PNID, and once setup is complete, enjoy!

(This may be a bit rusty, as it is from memory, apologies for any confusion in advance)

This may also help:
https://pretendo.network/docs/install/wiiu#pnid-setup
https://pretendo.network/docs/install/wiiu

Yeah this is the process.

So you will have 2 users on the Wii U after: 1 for NNID, 1 for PNID. and of course the PNID cannot match the NNID itself.