How can I copy, paste and edit links into address bar on STEAM?

Steam hasn't this feature for the main client

But there're many tricks to do that.

• First one is by Using the browser:

steam://openurl/URL

Example: steam://openurl/https://store.steampowered.com/

Put it into your URL address bar than Press Enter

Then Open!

 

• Second one by Steam Alt Window:
  You can also do CTRL+Click (On any linkable tab)
  and you will be able to edit

• The third one:
  is by sending the link to your friend on Steam

I hope that will be helpful for you, Thanks for reading this.