You'll need to create a channel by spending some of your on-chain funds, then manage your channel(
s)' liquidity since you'll only get outbound capacity upon establishing a channel.
More info in this thread:
Electrum Lightning Network walkthroughIt's worth to mention you need to pay TX fee when opening/creating and closing the LN channel.
Is there a way an Electrum watch-only wallet can have a fake wallet to show a fake amount if under duress? I know hardware wallets can do this.
Such feature doesn't exist. At best, you could create 2 wallet (one with tons of coins and one with small amount of coins) along with it's associated watch-only wallet. Obviously you need to place the main wallet (one with tons of coins) and it's watch-only file on different folder. But i doubt it's enough to fool criminal.