Translation:Unfortunately, I have to refuse.
I wonded if there should be a liaison in "suis obligé". Neither male nor female audio includes a liaison.
I found this information online: https://www.quora.com/French-language-Does-suis-ever-have-a-liaison (Summary: it's optional, including the liaison is more formal.)
I'd be glad if any native speakers could confirm this or futher elucidate.