I'm stuck at "The rogue harbour" (optional quest)- Complete Kurai's Contract

Hello guys!!
I am currently stuck at "The rogue harbour" Quest In which i got Kurai's contract and i attempted to complete it but failed. I was trying the challenge with a teammate. After we failed, i realised that theres no way for me to retrieve the contract or retry the challenge in some way!
I have no idea what i should do now, I want to complete the quest but i can't find Kurai's contract anymore!
Can anyone help me please?

The green quest contracts are optional side quest. They will continue to drop. Suggest you keep playing and you will get them again eventually, but don't get stuck on the harbor.