***Typo*** is a type of error already. See [*typo* in Merriam-Webster:][1]
>: an error (as of spelling) in typed or typeset material

>[…]

>Origin and Etymology of TYPO  
>short for *typographical (error)*

So I’d say, “Apologies for the typo,” or, especially in formal communication, “Apologies for the typographical error.”


  [1]: https://www.merriam-webster.com/dictionary/typo