Gaming MRDS combining items

[Translucentbill]

I had a question about how to use combining items in MRDS. I got the Beaklon thing and im not sure how to use it while combining, after selecting 2 monsters i figured it would be the small square in the center of the 2 monsters but i cant click it, do i have to unlock it later?

 

[Ringo619]

I had a question about how to use combining items in MRDS. I got the Beaklon thing and im not sure how to use it while combining, after selecting 2 monsters i figured it would be the small square in the center of the 2 monsters but i cant click it, do i have to unlock it later?

Just produce with the combining thing and the person will ask you if you wanna use this item