Don't use Muun. Muun is not a real Lightning Wallet. Last time I heard, they use submarine swaps, which can get very expensive when onchain fees are high... custodial getalby (as browser extention) or Wallet of Satoshis will do just fine for small amounts.

Phoenix is a real non-custodial lightning wallet, but fees can also become elevated when onchain fees are high and your initial channel doesn't have hihg enough capacity. If using phoenix, you should start with a large payment the first time to make sure it opens a large channel. I think, to be confirmed by other users of Phoenix.