If for some reason you need to use the legacy Text Core in UI Toolkit, you can enable it in UI Builder, USS, and C# scripts.
To use the legacy Text Core in UI Builder, do the following:
To use Text Core in USS, set -unity-text-generator to standard. The following USS example sets it for the root element:
:root {
-unity-text-generator: standard;
}
To use Text Core in C# scripts, set TextGeneratorType to Standard. For example:
textElement.style.unityTextGenerator = new StyleEnum<TextGeneratorType>(TextGeneratorType.Standard);