In AMMs, when a user provides liquidity, LP-tokens are minted and sent to the user. In Lendle, any asset deposited will give you 'L-tokens'. These interest bearing tokens represent their underlying asset, for example:
Lusdt for usdt that is deposited
Lwbtc for wbtc that is deposited
The value of the L-token is pegged at a 1:1 ratio with the deposited asset and all accrued interest is distributed directly to the L-token holders.
Converting L-tokens back to their underlying asset can be done on the Dashboard
Over at Mantle Contracts you'll find the L-token contracts.