Not very useful at the moment, but some may want to buy it for whenever international travel resumes.
It has positive reviews on Amazon US and currently at USD 13.95
Use the Undercover Hidden Pocket to keep important travel documents and personal identification items out of sight. This simple hide-away pouch slips onto your belt and conveniently tucks into the waistband of your pants. Made of a durable, yet discreet, lightweight nylon ripstop, this under-clothing solution has two mesh pockets for organization of a Passport and currency.