I think this must be the h-node page you found:
https://h-node.org/wifi/view/en/1725/Realtek-Semiconductor-Co---Ltd--RTL8723BE-PCIe-Wireless-Network-Adapter
It says "tested with the following kernel libre:5.5.10-gnu", which is much
newer than Trisquel's default kernel. I would start by installing a newer
kernel from jxself's repo: https://jxself.org/linux-libre/
The description on the h-node page provides further instructions. Read them
through, and if you don't understand them ask for help here.
