Like Horvald said, there does not appear to be any native way to have a player-initiated secret roll for the DM. And, frankly, I don't think there should be. That way goes DDoS-esque spamming of the DM. Considering how slow roll20 can be at times, if you never got any indication that the roll went through, you might select it multiple times. In addition, having a player-initiated secret-roll requires that the player KNOW the DM wants a secret roll, which screws up at least half of the reason for them.
The following code, placed on the DMs Macro Bar, would allow it, though. I don't remember where I originally got it.
/w gm **@{selected|character_name}** secret ?{What secrets... |
Perception, Perception [[1d20+@{selected|perception}]] |
Arcana, Arcana [[1d20+@{selected|arcana}]] |
Crafting, Crafting [[1d20+@{selected|crafting}]] |
Diplomacy, Diplomacy [[1d20+@{selected|diplomacy}]] |
Medicine, Medicine [[1d20+@{selected|medicine}]] |
Nature, Nature [[1d20+@{selected|nature}]] |
Occultism, Occultism [[1d20+@{selected|occultism}]] |
Religion, Religion [[1d20+@{selected|religion}]] |
Society, Society [[1d20+@{selected|society}]] |
Stealth, Stealth [[1d20+@{selected|stealth}]] }
The problem with this code is that it doesn't include anything that would be in the notes. Though that shouldn't be too difficult to add. Let me see what I can do.
Ah yes. A quick and dirty modification:
/w gm **@{selected|character_name}** secret ?{What secrets... |
Perception, Perception [[1d20+@{selected|perception}]] @{selected|perception_notes} |
Arcana, Arcana [[1d20+@{selected|arcana}]] @{selected|arcana_notes} |
Crafting, Crafting [[1d20+@{selected|crafting}]] @{selected|crafting_notes} |
Diplomacy, Diplomacy [[1d20+@{selected|diplomacy}]] @{selected|diplomacy_notes} |
Medicine, Medicine [[1d20+@{selected|medicine}]] @{selected|medicine_notes} |
Nature, Nature [[1d20+@{selected|nature}]] @{selected|nature_notes} |
Occultism, Occultism [[1d20+@{selected|occultism}]] @{selected|occultism_notes} |
Religion, Religion [[1d20+@{selected|religion}]] @{selected|religion_notes} |
Society, Society [[1d20+@{selected|society}]] @{selected|society_notes} |
Stealth, Stealth [[1d20+@{selected|stealth}]] @{selected|stealth_notes} }
You may be able to do them in bulk with a Pro membership. I know for a fact you CAN do them in bulk with an additional extension. (VTTes in this case.)