Not a great picture but it's almost a certainty if house was built before 1980. Only sure way is to have it tested. Are you looking to disturb it or just curious?

Just curious. So the silver part is asbestos?

The “silver part” is probably tape. You asked “how to tell”, are you able to purchase a $5-10 asbestos test kit?

I guess my question really is which part should I test?

I recommend following the test kit manufacturers instructions.

Perhaps, your question should be, do I really have the ability to do this.

The white fabric is the suspected stuff. Here's some background: https://www.asbestos123.com/news/asbestos-in-heating-ducts/

Thanks, I guess it looked pink to me that’s why I was asking. The pictures I’ve seen were white.

Asbestos sheets have white color or a little pale not pink.