Apply your text as an image texture onto a 3D plane prop. You can edit this texture in an external editor like Photoshop; saving it will automatically update the text in your iClone scene.
There are Marketplace plugins like iText RL designed to help manage text props, though availability for specific versions may vary. 2. Creating Text-to-Speech (Animation) reallusion-iclone-pro-8-01-0531-1-full-version
iClone does not have a direct "type 3D text" tool built-in, so you typically import it as an object or use a texture: Apply your text as an image texture onto a 3D plane prop