Setting space between some items in stack view
iOS 11 and above
stackView.setCustomSpacing(32.0, after: headerLabel)
For more info: Stack View Custom Spacing
It's an answer based on Lumialxk's reply. Choose the stack view you want to work on, and change the spacing property to your desired value.
Inside your horizontal stack view have three more horizontal stack views so that you can have control over spacing and distribution for each item. See screenshot below: