Since PHP 7.x it is recommended to use the native password_hash() function (read more).
MD5 should be avoided since there are plenty of md5 dictionaries for helping to "crack" MD5 passwords like f.i. https://crackstation.net/.
Note: since password_hash() is native, therefore there are no dependencies with an external library.
The hash of gives
Sample PHP code:
Store for instance the hash of this password in a database or any protected file (best outside your public folder) and don't use anymore your password in plain text but just verify the hash using password_verify().
Info: the hash will start with '$2y$' when the used algorithm is BCRYPT and with '$argon2i$' when Argon2i was used (which is much better).