Electrum ---> Muun

Here's the situation: I hold my Btc using Coldcard + Electrum. I'd like to transfer some sats (around 50$) to Muun wallet so I can get comfortable using Lightning network when paying for coffee or other small things from my iPhone.
What's the best way to do this? Is it by sending On-chain Btc on Electrum to Lightning on Muun? Any other methods?
Thanks