I want so send small satoshis to 20 btc address that a paper wallets, the values are small and the security is not of prime issue. This is for educational purpose.
What do I need to do to be able to send fund out satoshi from the LND wallets to my 20 receivers?
You can't send funds from your channel to bitcoin addresses.
The funds has to be in on-chain to be able to send to paper wallets.
For that, you'll have to close the channel and proceed to create an on-chain transaction with multiple outputs.
Since you only have 1 channel open, "
close all" will do:
https://github.com/rootzoll/raspiblitz#close-all-closing-all-open-channels