Where is the "protein" in pre workout coming from?

This is a preworkout I used and I was quite shocked to see 81kcal from seemingly nothing except a quite random 19g protein??? My best guess is it has something to do with BCAAs as whey or other protein types are not listed.

Any ideas? Are they just lying about the protein?

This is a preworkout I used and I was quite shocked to see 81kcal from seemingly nothing except a quite random 19g protein??? My best guess is it has something to do with BCAAs as whey or other protein types are not listed.

Any ideas? Are they just lying about the protein?