@Rajaibrahim: While your S24 Ultra is connected to your display via DeX, check the Navigation bar at the bottom of your phone's screen, and tap the white rectangle symbol with the black border to use the mobile device as a touchpad. For further clarification, please take a look at page 128 of the user manual by following the link below.
I hope this helps.
Hi Andrew, thanks for your reply, but , still not able to sort this out,
i have attached the screenshot, please take a look
i have attached the screenshot, please take a look
@Rajaibrahim: Try swiping down once again to expand your notification panel, to see if further options are made available to you. Alternatively, tap the DeX notification to see if this expands your options. I also recommend tapping on Device control, or checking the DeX display on your external screen to see if you can see an option to enable the touchpad from here.
i have attached further screenshot 
@Rajaibrahim: Having looked into this further, you should see an option in your Notification panel that reads 'Use your phone as a touch pad", however I can see from your screenshots that this option isn't available to you. Do you happen to have a mouse connected to your device? Aside from the missing touchpad option, is DeX functioning as expected on your external desktop display? Have you tried heading to Settings > Connected devices > Samsung DeX > Start DeX, to see if launching the feature in this manner is of any help? Alternatively, try removing your Accessibility button, just in case this is preventing the touchpad option from showing in the Navigation bar.
