Sumitomo Mitsui Gold Card travel insurance if I pay a return flight date change

Hi everyone,

I’m a Japan resident and I have a Sumitomo Mitsui Gold Card.

I already flew from Sydney to Tokyo on a round-trip ticket, and now I need to change the date of my return flight from Tokyo to Sydney. I am not Australian.

I did not buy the original ticket with the Gold Card, but I plan to pay the date change fee (or fare difference) with it.

My questions are:

1. Will paying the change fee with the Gold Card be enough to activate the card’s travel insurance (利用付帯)?
2. Or does the original ticket also have to be purchased with the card?
3. Is the insurance provided directly by Sumitomo Mitsui, or by a separate insurance company? If I need to use it, who do I actually contact?

Sorry for the many questions, but this is my first time trying to rely on the Gold Card for insurance and I’d like to know how it really works from people who have used it (not from AI …).

Any advice or experience would be really appreciated. Thanks!