Breeding red eyed tree frogs

Hi Guys, I had been hearing calls from my red eyed tree frogs and they were 1-2years old so I decided to build a rain chamber using a Exo terra 24x 24x 36inch (height) with rain bar and some love plants to let them breed but every time a pair to amplexus they would last for 2-4days but no eggs,Why is that so?
Could any one in this forum which had bred red eyed tree frogs explain why is it so that a pair of frogs would amplexus for 4days but no eggs ?