I ended up doing research on the Astral Trainers race to answer this question:
https://www.tibiaqa.com/21261/who-are-they-and-where-did-the-miunir-breed-come-from
and I didn't find any documents, just sounds of the monsters of the race.
Broken Shaper: "<grunt>"; "Raar!!".
Twisted Shaper: "Ti Jezz Kur Tar!".
and the sound of the Shaper Matriarch that you mentioned, which in turn blames other creatures for the fall of their race, they were responsible and were the last holders of the knowledge that includes their language, their only connection between the Formators was their knowledge .
Shaper Matriarch: "Kur Tar Razka!"; "Tar Marra Zik Tazz!".
On the question: what language do Astral Shapers speak and how can I learn to speak their language?
Of all that I researched feathers, a breed that adapted its culture using the same language and managed to translate that it is Miunir that is in the answer I mentioned above. according to NPC Albinius, the only records are kept in old chests and others stolen by other creatures.
"Albinius: The Shapers are eager to share and document their wisdom in any way possible. They knew many ways to preserve information, some of which are probably not yet known or even understandable by us ...
Albinius: Right now, the Shapers' most useful records are the various shots they wrote. You can still find some of them in the vicinity of Thais, some locked in old chests, others stolen by wild creatures. ...
Albinius: They certainly use them for terrible and profane purposes, so getting them back would be a service for the Shapers. In addition, these tomes can contain everything we need to finish the temple."
Shaper Matriarch - Tibia Wiki
Astral Shapers - Tibia Wiki
Albinius - Tibia Wiki