Due to kernel update in ubuntu you are no more able to get the header file for your wifi in lwfinger rtlwifi_new repo so this repo contains code to install rtl8723de wifi module in your ubuntu laptop or pc. This works for kernel version>=5.0 as well.

Following are the steps:-

sudo apt-get install build-essential dkms

git clone https://github.com/smlinux/rtl8723de.git

sudo dkms add ./rtl8723de

sudo dkms install rtl8723de/5.1.1.8_21285.20171026_COEX20170111-1414

sudo modprobe -r rtl8723de

sudo modprobe rtl8723de

Done!!!