Adding a new sidebar in the template

I wanted to add a menu to the left sidebar when I open my articles, but on my homepage the sidebar should be on the right. Since you can enable only one position for a sidebar in the template options, I wanted to add a new custom position for the left sidebar.
How can I achieve this?
Note: I've read the article about adding a new module position (https://www.gavick.com/documentation/joomla-templates/customizing-joomla-template/how-to-add-new-module-position) but I couldn't get it to work properly.

This kind of custom job is not supported by our technical support.
You can hire any Gavick Moderator, interactive agency or frontend freelancer for this payed custom job.