i am trying to install wifi adapter by following command shown here but got this error

I have recently installed ubuntu 18.04 in my system ,everything goes well except the wifi is not working . it shows “Adapter not found”. then i Tried the solution shown in “WiFi adapter not found in Ubuntu 18.04 [duplicate]” but got this error in foll0wed command

sudo modprobe rtl8723de

modprobe: ERROR: could not insert ‘rtl8723de’: Operation not permitted