You can drop it into Imageoptim: https://imageoptim.com/mac – if you turn on ‘lossless’ compression in settings and are ok with some dropoff in quality, it will drastically reduce your filesize.
Another thing you can try: Export as MP4 video, and use the Gifski software to fine tune it: https://apps.apple.com/us/app/gifski/id1351639930?mt=12
Both are free. (Here’s some more tips: Animated GIF export - how can I reduce size? )