moving similar threads after first post or in sidebar

[Jaffery]

Hi,

I am looking to move similar thread either after first post or in sidebar, I tried adding this
following in postbit_legacy

{vb:raw similarthreads}

But nothing appears, I have figured out how to show custom content / ads after first post but similar thread doesn't appear.

I guess I need to register variable before using it in template but I have no idea how to do that, I see details here : https://vborg.vbsupport.ru/showthread.php?t=228078 but frankly I would prefer someone knowledgeable to show me steps so that I can understand things better.

Thanks