the output is not registering that the h6 font size of 14px is continually being marked incorrect when i put it in
when you have a question related to a challenge, please provide your code and challenge link. and as many details as you can. It is extremely difficult otherwise.
In this particular case, if you put a dimension of 14px and the font size is not recognised as such, it may be that your browser has a minimum font size set higher than that - this is a thing you need to change in browser settings.