Anima is able to export responsive interactions and breakpoints of a given frame/artboard into one HTML file (both absolute position and auto flex).
To do so:
Open the Zip file from your downloads. Find the correct HTML file and open it in your browser, when you adjust the size, the display should be responsive!
You are not able to export different artboards/frames into one HTML file, only responsive code for the same screen. Other artboards/frames will appear separately within your Zip file.
Check out this article to learn more about setting up responsive breakpoints with Anima.
Get started with these tutorials: