'It is immoral to use textbooks with profane words in them because it is not right for our children to be exposed to disrespectful and ugly words.' Which logical fallacy is committed in the above argument?

The claim that such textbooks are immoral rests on saying the words are disrespectful and ugly, which merely restates being profane.

The reason offered is only the conclusion put in other words.

Nothing independent is given to support the moral judgement.

An argument whose premise repeats its conclusion moves in a circle.

This is the fallacy of arguing in a circle, or circular reasoning.