how do I change my photo's from a .html. to .jpg.

Hello,

You can convert image file types using the Preview App.

Convert image file types using Preview on Mac - Apple Support

"Convert image file types using Preview on Mac

Preview can convert image files to many file types including JPEG, JPEG 2000, PDF, PNG, PSD, TIFF, and others. This can be useful if you share files with people who use other kinds of computers or if you want to open files in apps that don’t read all file types.

1. In the Preview app  on your Mac, open the file, then choose File > Export.
2. Click the Format pop-up menu, then choose a file type.
3. If you don’t see the file type you want, press and hold the Option key and click the Format pop-up menu to see specialized or older formats.
4. Depending on the file format you choose, additional options may appear. If you choose JPEG or JPEG 2000, you can adjust the image’s quality. If you choose PDF, you can choose a Quartz filter to apply to the image, and you can encrypt the image so that only those with the password can view it.
5. Type a new name, or choose a new location for saving the converted file, then click Save."

I hope this helps.

Or could you mean HEIC to jpg? HEIC is a new high efficiency format used by Apple and sometimes not recognized by older viewers. In your Monterey OS, both Preview and Photos can read HEIC and export jpg. You could use Photos to load a bunch of pictures, then select them and use File>Export xx Photos and choose jpg.

Then again, if HEIC isn't what you mean, let us know more details about your pictures.

.html is not an image type. It's a format for a web page. Images on web pages would be assists attached to the page. Can you give us any information about the source of these images?