where can i do a testnet Lightning Network Reverse Submarine Swap? i have Testnet LN Node,
i have created a wallet,
i have send on-chain funds to that wallet
i have connected to several peers
i have created several channels, all of these are outgoing one side funded channels,

i want to do a reverse submarine swap, i mean Pay in LN and receive in BTC

LN --> BTC 

this site offers the other way https://submarineswaps.org/

the purpose of these is to reverse a channel, or the half capacity of channel to be ready to receive LN payments. 

of course i could just spend money, but the idea is to reverse the channel without loosing money (loosing is simulated as its in testnet)

thanks
you can try sideshift.ai or zigzag.io the first one supports testnet but is still invoite only. For zigzag.io I think this service is only offered on mainnet.