The Dinka alphabet as used by South Sudanese Dinka people writing the Dinka language is Latin, adding some letters adapted from the International Phonetic Alphabet to the ISO basic Latin alphabet. The current orthography is derived from the alphabet developed for the southern Sudanese languages at the Rejaf language conference in 1928. Prior to this, several attempts at adapting the Arabic and Latin scripts to the Dinka language were made, but neither effort was met with large success. Christian missionaries were essential to the development of what became the Dinka alphabet.
As you can see, Dinka does not use f, q, s, v, x, and z; and h is used in digraphs only.
Note that ɛ̈ (open e with trema/umlaut) and ɔ̈ (open o with trema/umlaut) do not exist as precomposed characters in Unicode and must therefore be generated using U+0308, the diaeresis combining diacritic.