If the selection in your bet slip can be played with a FreeBet, the respective FreeBet will be offered to you automatically in your bet slip. You can then play the selection as a FreeBet or use the FreeBet at a later point in time.
A FreeBet is an amount that can be used to place a sports bet. If your bet wins, the net winnings (winnings minus stake) will be credited as cash into your account balance.