The default arrowheads cannot be changed. You can only enlarge it by increasing the thickness of the line. You can draw your own with the pen tool.

How can I draw a clean arrow with the pen tool?

Hold Shift to draw strokes at 45° angles.

This is a unnecessarily complex work around for what is usually a standard function to set the arrow size as a percentage of the line width. Hopefully Figma will put this on the development backlog.

That’s NOT cool.

A solution. Not a good solution.

Lol why you so mad about a simple task like this. For rough drafts the default arrows are more than enough. For a real design there are many parameters to arrows: angle, length, width — so you’ll need to create custom ones most of the time anyway. 🤗

It would be beneficial if the feature for modifying the arrow heads aligns with CSS standards so that whatever specs are applied are easy to move over to development.