I had Muun but it didn't work, switched to WoS. Thanks!
Plebstr is great. If you don’t have a wallet already, Wallet of Satoshi is a popular one and has good support for Nostr features. You can download it from the App Store and they’re here on nostr nostr:npub1hcwcj72tlyk7thtyc8nq763vwrq5p2avnyeyrrlwxrzuvdl7j3usj4h9rq . Once it’s setup, copy your Lightning address from Wallet of Satoshi (it looks like an email address) and paste it into your zap settings in Plebstr. Screenshots below for reference. You can also set it as the default wallet for sending on that same settings page. 
Discussion
Perfect! Yea Muun doesn’t have full support for zaps and Lightning addresses which is what you need on Nostr. Wallet of Satoshi, Alby wallet (https://getalby.com), and Lightning Tip Bot (https://LN.tips) are all good wallets with Nostr support. They’re all custodial, so it’s best not to keep a large amount on them. Think “pocket money” amounts. There are better options for self custody of larger amounts but those don’t have Lightning address support for nostr yet.