DSMX frame rate menu selection?

Jumper T8SG v2 with version
t8sg_v2_plus_v5.x.x-2018-04-19

I contacted jumper, they said I can select 22 or 11ms frame rate for DSMX.

I cannot find it anywhere and they only responded with telling me to look on YouTube or google. Did that before I contacted them and still cannot find it.

Any help appreciated, thank you.

When you select DSMX as the protocol press Enter on it and it will take you to a settings page where you can find High Speed. That's only valid if you have between 8 and 10 channels configured for your model, otherwise won't do anything.