You need to open a lightning network channel. Some lightning wallets will do that for you. You can't pay a lightning invoice from a regular bitcoin address. Check out @DarthCoin's guides for a better explanation
Is your LN wallet a custodial wallet (e.g., Blue Wallet)?
With Wallet of Satoshi and CoinOS, you can deposit on-chain, and then access (i.e., spend) those funds via LN.
Otherwise, how do I fund a LN ‘wallet’?
You can use an exchange that has support for LN. You can either buy bitcoin and withdraw LN, or some (e.g., Bitfinex) will let you deposit on-chain and withdraw via LN. Some (e.g., Paxful) charge a fee for withdrawing via LN.