how to get private key from passpharase in php? i have a passpharase bitcoin, but i don't know how to get private key from my passpharase. I tried using blockchain and electrum and it worked. but here what I need is to find the private key using php. 

please help me how to find the private key?
if you have mnemonic seed phrase
use offline
https://iancoleman.io/bip39/