How I can customise webpage of webapp

Hello there, I want to customise webpage ( hide some buttons and sidebars ) for my specific tasks.
I read about plugins and its very usefull feature.
But there are no examples how to modify display of webapp, for example I want to hide button “create private channels”
Tnanks for any recommendation
P.S I dont want use CSS for this

Hi @2ur1st, thank you for reaching out.

Here is documentation on how to build plugins:

Here are also instructions for customizing Mattermost: