how to add table of content to left sidebar?

Hi there,

To do it without a plugin or the kind of code that a plugin uses, and to manually type this, you would need to NOT use a sidebar.
Instead create a 2 column layout in your post. Then you can add whatever you like to your 'fake' sidebar.

Recommendation: use a Plugin for this kind of thing, as they do all the grunt work for you.

"Recommendation: use a Plugin for this kind of thing, as they do all the grunt work for you."

why?

only because it takes time?

Plus, I can make the table of content in the content instead of the sidbar.

why?

only because it takes time?

I would say there are decent plugins out there that offer TOC functionality so that's your best bet.

It's up to you though - if you are comfortable with creating custom solutions then go ahead.

However, this isn't something we can support in the forum here:
https://generatepress.com/what-support-includes/

If you need a custom development service, then consider using a service as Codeable suggested at the bottom of the page.

Or post the question in a WP general forum like this one:
https://wordpress.stackexchange.com/

Thanks for your understanding :)