How do I convert heic to jpg as my pc can't open heic photos?

If the main goal is just getting the photos into your slideshow app, converting them to JPG is probably the easiest route. Use an offline converter for a large batch and keep the original HEIC files untouched, since JPG conversion can reduce quality.

Also, if only a few photos fail to convert while the others work normally, check those files separately rather than assuming the converter is the problem. A damaged HEIC can sometimes still look fine in a phone preview but fail when another program tries to process it.