Yes, I confirm that 諦めない means "don't give up" (It actually doesn't say "NEVER give up.") The last two hiragana are "na" and "i" which makes up a verb conjugation "nai" which is the negative form of the plain verb 諦める akirameru (to give up). If you want, you can consult a legitimate Japanese-English dictionary like jisho.org, search kanji by radical, and see what it comes up with.

Have a good day.
Stop fighting.