L-BTC is not BTC. L-BTC a sidechain and afaik Electrum doesn't support it. You may want to use Blockstream Green wallet for L-BTC, since both are Blockstream "products". But I don't know if it supports LN.
Or use an actual Bitcoin wallet that supports LN and forget about L-BTC.


PS. Imho there are for LN easier options than Electrum if you are not a tech head.

If you open a LN channel it won't make sense to use it just for one withdrawal because you are likely to pay more fees at the end than if you had requested an on-chain withdrawal. So if the solution is interesting if you have to use LN for other transactions or if you are wiling to make other withdrawals through LN in the coming weeks or months before closing your channel. Once you have open a channel you will need to send funds to the exchange or elsewhere in order to get some receiving capacity, after that you will just need to generate a LN invoice in Electrum with the amount you want to receive(smaller than the receiving capacity of your channel) and paste it on the exchange.

so you think i should use lightning channel if im doing like 10 small transactions of around 20$-30$ each monthly ?

where to trade altcoins if you dont use an exchange  
 im trading in exchanges then withdrawing my earnings to my Electrum wallet

Use decentralized exchanges, p2p trading, and don't waste time with bunch of shitcoins.

You can find some tools for non-kyc trading on kycnot.me website.