@Khoosbu. Not sure why they don't ask for travel documents. never heard from anyone with same case where they ask for TD. But it is clearly mentioned on USCIS link under Refugee Travel Document section which mentions GC granted through Asylun need TD to travel document to return to the United States.

So you have to decide between
1) Travel experience from people like me

2)Apply for TD, 60-90 days to receive your TD, It also depends when you are travelling.

Here is the link from USCIS.
https://www.uscis.gov/green-card/green-card-processes-and-procedures/travel-documents
(Go to Refugee Travel Document section )