First, you should go to this official link below and select the version you need to downloads.
https://pinyin.sogou.com/linux/
like this:
Open a terminal with " Ctrl+Alt+t " and follow these commands:
cd Downloads
sudo dpkg -i sogoupinyin_2.2.0.0108_amd64.deb
If there's a lot of dependency problems in the process, please use sudo apt-get install -f to solve them:
and now, it has been installed successfully, you can enter into system settings and switch input methods.
change the keyboard input method system into fcitx.
Finally, Restart is ok.