You can set up a LNbits Hub and open a wallet for him? (But you'll need to manage channels and liquidity) If he wants a fully self-custodial solution in LN he needs to manage channels and liquidity, there's no other way.

For Phoenix, it actually manages liquidity for you, it keeps one single channel with ACINQ and charges you a fee every time you need to increase capacity/liquidity on the channel

For this reason, I can't wait to see wallets integrating

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