This is possible using the Plugin API, and I already answered you earlier here: Fixed frame in presentation mode - #2 by tank666.
Another related topic: Expose missing fields from the API.
Can you provide me a code example of how to use it, as the documentation is not helpful. Neither is your reply, saying, yes it’s possible, without an example is not very helpful. Their is no help around this “numberOfFixedChildren” online.
let numberOfFixedChildren;
const newFrame = figma.createFrame();
newFrame.name = "newFrame";
// Align newFrame to the top left of parentFrame
newFrame.x = 0;
newFrame.y = 0;
const imageNode = figma.createImage(imageData);
// Append the new grouped text to the frame
newFrame.appendChild(imageHolder);
// Append the new frame to the parentFrame, not the page
parentFrame.appendChild(newFrame);
How would the newFrame be fixed?
parentFrame.numberOfFixedChildren = 1;