A friend of mine recently had his first child and we are all going to visit and bring gifts. I want to gift $10 in btc not to be accessed until his kid is an adult, by which time it will be worth a lot more or nothing at all.

I'm trying to figure out the best way to do this so that in 20 years the btc can still be recovered. Do I make a wallet, write down the seed phrase, send in some bitcoin and then destroy the wallet? Or do I write down the private key for the specific address where I send the bitcoin to? And which wallet? Electrum doesn't use BIP39, but a BIP39 seed phrase isn't guaranteed to work with every BIP39 compatible wallet either... What about derivation paths?
Is there a secure way to generate a paper wallet offline with a QR code and everything?

I have no experience with paper wallets so any advice is welcome.