HOW TO SEND A TRADE OFFER - DESKTOP
STEP 1:
Click 'Their inventory'
STEP 2:
Click 'Select an inventory to view items you can trade'
Then, click 'Dota 2' or 'Counter-Strike: Global Offensive' (Or another game if applicable)
STEP 3:
Under 'Looking for a specific item?', type in the keywords of the ordered item(s),
Example: 'm4a4 buzz field' (weapon type, skin name, exterior/wear). The relevant items will appear.
STEP 4:
DOUBLE-click the item, it will move to the right.
STEP 5:
Repeat step 3-4 until you have finished selecting all the items you have ordered.
Then, click 'Click here to confirm trade contents'
STEP 6:
The 'Make Offer' button will turn green.
Click the 'Make Offer' button and you are done!