Free agency begins on June 30, meaning that multiple NBA players will be able to agree to the terms of a new contract verbally.
Every season a whole host of NBA stars head for free agency, and interested teams fight for the chance to acquire their desired players to strengthen their roster ahead of the following campaign. Trades can be discussed during certain times of the year, and also throughout the offseason, but the NBA is strict when it comes to free agency.
The league issues heavy fines and punishments for 'tampering', which can be breached if any organisation member, coach, player, executive, or owner speaks to a player on rival teams to lure him to join their team. That doesn't mean that some organisations don't push the boundaries, as Magic Johnson found out back in 2017.