As of today, there are still no optimal solutions to get Bitcoin on the Lightning network directly. o one more step must be taken first to get Bitcoin on the Bitcoin Blockchain (so-called "on-chain") and then transfer them to the Lightning network.
*This is not a solicitation to buy or invest in Bitcoin. The value of Bitcoin relative to other currencies (e.g. CHF) is fluctuating and therefore the value of Bitcoin in CHF can go down or up on a daily basis. This is not an exhaustive list or recommendation of any service and is for information/educational purposes only. No liability is accepted in this regard.
These methods are not suitable for holding significant amounts of Bitcoin and should be treated like cash in the wallet. The best method of keeping Bitcoin is always on physical devices (so-called Hardware Wallets) in one's own custody. An exhaustive list of resources about Bitcoin can be found at
https://www.lopp.net/bitcoin-information.html