How can I reduce the file size of HEIC file to use on the web?

I want to post some pictures on the blog on my website and the file size is too large. I've got the files saved on my desktop (downloaded from the cloud - there are probably simpler ways to do this but between me and my hubs who set it up this is the best we know to do). How can I reduce the file size? I googled that I should be able to right click and save as but this isn't showing as an option.