Are you trying to send to cold storage from Phoenix?
If so, just hit send, and paste or scan the address. It will recognize an on-chain destination and configure the transaction with miner fees as needed 🫡
Discussion
Answer I was looking for. Haven’t tested just because I dived in today and didn’t want a smol UTXO in CS. So I hit send to play around and it didn’t show anything relating to Bitcoin address so I was curious 🫂 
Glad I could help! Looks a tiny bit different there (I’m guessing you’re on Android, and I’m used to iOS), but same thing essentially 🤙