How to link my Marketplace.tf profile and my backpack.tf profile

[nutellafree]

I saw some trade on bp.tf where there is also a link to buy the item on marketplace, how can i set up that, i can't find the option on the settings of both sites

 

Thank you !

[D.Alex]

Backpack.tf, your Avatar in the right top corner, menu Settings, tab Connections →  https://backpack.tf/connections

[nutellafree]

Thanks a lot !