The simplest method to convert wrapped BTC is to utilize a no-KYC exchange like https://sideshift.ai
SouthXChange: https://www.southxchange.com/ FixedFloat: https://fixedfloat.com/ SideShift: https://sideshift.ai
Aqua uses a custodian company called sideshift.ai and the address is a custodian address they temporarily
There are a couple other swap services that offer (L-BTC LN BTC) as well (SideShift.ai and Flyp.me),
Here are a few options for simple swaps https://changelly.com/ https://sideshift.ai/ https://stealthex.io