how send knx 1/2/3 8-bit value 128

dear KNX support team
good day to you.

i have a audio actuator connected to my project through IP.
i wanted to connect it to my project scene to switch on/off with other scenes.
i contacted the audio actuator maker an they sent me the structure but i dont know how to setup and he is asking me to send 128 scene to save the scenes by BUS monitor.

i will post their reply here with some comments from my side for your reference.

before saving/restoring scenes, you must tell which zones will take part in that scene. this is done by 1-bit messages to

configuration / zones / zone / knx bindings / GA scene for each zone.

--- example --

please follow this all step by step.

1. store a scene with 2 zones
1.1 switch zone 1 on (fm tuner), zone 2 off.

1.2 configure in zone 1:
configuration / zones / zone 1 / knx bindings / GA scene 1/2/3

1.3 configure in zone 2:
configuration / zones / zone 2 / knx bindings / GA scene 1/2/4

1.4 tell zone 1 and zone 2 that they will take part
in the next scene:
- in the ETS group monitor, send 1-bit value 1 to 1/2/3
- in the ETS group monitor, send 1-bit value 1 to 1/2/4

now zone 1 and zone 2 know that their current state should be saved when the next scene save command is received.

but no scene is saved yet!

 do this part correctly but the next part is a bit difficult

1.5 configure globally:
automation / knx / setup / group address for scene save/restore 2/1/0

1.6 send command to trivum to save the current state of zone 1 and zone 2 as scene 1.
to do so, send from the ETS group monitor an 8-bit value 128 to 2/1/0
because "128" means "save the first scene".

i dont understand this. how i can send a 8-bit value 128 from group monitor??

Now the system saves scene 1 with this informations:
- zone 1 should be on, with FM tuner.
- zone 2 should be off.

2. recall a scene with 2 zones
2.1. switch all zones off
2.2. send command to trivum to recall scene 1.
to do so, send from the ETS group monitor an 8-bit value 0 to 2/1/0
because "0" means "recall the first scene".

i don't understand this part too.