You can withdraw money from your Lifetime ISA (LISA) at any time. If you are under 60 and not using the money to buy your first home, you will pay a 25% government charge on the amount you withdraw. This means you could get back less than you put in.
Once you request a withdrawal, it may take up to a week for the money to reach your bank account.
For more details, visit the official government site on LISAs.