Episode 15 was the finale of the Nue arc(I think). Now in this episode the jougan didn't appear, but Toneri appeared for the first time and he revealed that the Boruto's eye is called Jougan. That was it.

Can Boruto activate Jougan?

While Boruto can't control the Jougan yet, he will eventually learn to control it. Right now, fans can only wonder what Boruto will have to go through to master that control. Boruto's Jougan and karma both show up randomly; however, someday he will be able to control the Jougan.

Does Naruto know Boruto has the Jougan?

Boruto would be a celestial Jinchuriki, a ninja with interstellar power and chakra control. Only a few characters know about Boruto's Jougan. Naruto knows about Boruto's eye as well as Sasuke. ... Only over the course of the series has it shown to contain abilities reminiscent of the other Dojutsu eyes.