Hi there @Saulo,
As you're in Synchronous mode, you'll need to define a prliminary sketch for the base "Tab" to be created from.....please yourself if that sketch has dimensions or relationships placed on it, or not, as these can be added afterwards also.
At the bottom of the graphics area, there is a "PromptBar", this will give the user continuous feedback as to what input the system is looking for next....it will also provide tool descriptions when the cursor is hovered over them, as is the case in your screen shot, hovering over the "Tab" command button. If you know the name of a command but can't find it, use the "Command Finder" to search the system for you, and it will list out what it finds, and mouse over them and the system should show you exactly where that command is sitting.
I recommend your going through some of the tutorials in the "Help" area, to get a better feel for where things are, and the typical work flow for new Solid Edge users.
Design Manager Streetscape Ltd
Solid Edge ST10 [MP3] Classic [x2 seats]
Windows 10 - Quadro P2000
you need to understand the concept of object-action and/or action-object
some commands are only one way or the other some can be both.
in this case those commands are object-action. they require an object (a sketch) to run the action (tab)
so create your sketch and you will then see the commands become active...