Airdrop Photos from iPhone are HEIC format? Can't drag and drop those...

I frequently use my iPad or iPhone to transfer photos to my laptop for use in a website or other apps. However, since iOS 13, those images are transferring as HEIC files, which I've never heard of, and my computer won't allow me to simply drag and drop those into Squarespace or other apps...they simply don't support that file extension.

I can open them in Preview and save them back out, but I don't want to have to do that...it used to be simple...Airdrop the file, drag it onto something else to open.

Is there a setting to make this a PNG or JPEG format as a default? I don't like this HEIC thing...I'm a graphic artist, and it's nonstandard. It's taking twice as long to do anything because of this. I've finally made the change to PNG files, even though they seem to be larger than JPEG files, but changing this again is not a good thing!

Thanks!