You can get them through APIEnv_GetProjectNotesID and modify them through APIEnv_ChangeProjectNotesID.
You can also use ACAPI_Goodies(APIAny_SetAnAutoTextID) and ACAPI_Goodies(APIAny_GetAutoTextsID). You can find the list of autotext here, just remove "<" and ">".
~ReignBough~ ARCHICAD 26 INT (from AC18) Windows 11 Pro, AMD Ryzen 7, 3.20GHz, 32.0GB RAM, 64-bit OS