(Modern) Use App/Browser how to dynamically set Chrome vs IE in library

I am creating a custom activity that logs into a particular web application. I want whoever uses the custom activity to designate Chrome vs IE by parameter.

With the classic Use Browser you could change a pulldown between the different browsers.

With the modern Use Application/Browser it doesn’t seem to have this option. It detects which browser it is when you indicate the target. How can I change it from Chrome to IE? If it can be changed, can it also be set dynamically via variable/parameter?