Doesnt set the line 4 in the fastboard to 1 element of a queue

[foggy topaz]

    if "%event-inputkeys%" contains "sneak key":
        if {advParkourActive} is false:
            stop
        else:
            if player is on ground:
                stop
            make player invulnerable
            set player's velocity to vector(0, -10, 0)
            draw 50 smoke particles with velocity of vector(0, -0.05, 0) at player
            add 1 to {slamStorage::%player%}
            add "&bSLAM" to the start of {styleBonuses::%player%}
            **set line 4 of player's fastboard to the first element of {styleBonuses::%player%}**
            if {slamStorage::%player%} <= 10:
                send actionbar "&c%{slamStorage::%player%}%"
            else if {slamStorage::%player%} < 9:
                send actionbar "&e%{slamStorage::%player%}%"
            else if {slamStorage::%player%} <= 20:
                send actionbar "&a%{slamStorage::%player%}%"
            if {slamStorage::%player%} >= 20:
                set {slamStorage::%player%} to 0
                set velocity of player to vector(0, 2, 0)
                draw 100 smoke particles at player
                add "&cHYPERSLAM" to the start of {styleBonuses::%player%}
                set line 4 of player's fastboard to the first element of {styleBonuses::%player%}
            wait 10 ticks
            make player not invulnerable```

[jolly sluice]

that's because it's not a list

{something::another_thing} is a variable
{something::*} is a list where the index another_thing can be found