@konrad.sopala First, thank you for your help! I already came across the docs on Lock UI Customization and also already use the suggested rule.
To clarify my problem, that’s the text I want to customize.
There is nothing available about this in the documentation you mentioned because only customization of the Lock Login/SignUp UI is covered. It would be great if this would also be possible!
I tried to customize it with a little hack via css (::after). However that didn’t work.