I am on 63 and I already have it. It's just that it was disabled by default and you needed to enable it in about:config. I used to use the multiple tabs handle

I am on 63 and I already have it. It's just that it was disabled by default and you needed to enable it in about:config. I used to use the multiple tabs handler addon but it stopped working once I moved to 60esr so I was glad that they introduced it back.