This error can cause due to the following 2 reasons.
1 - You are trying to execute the grade command outside the respective project directory.
You have to be inside the workspace/-QMONEY directory where you have cloned the repository.
Refer to the following image for the right directory.
2 - Gradlew command is not executable.
Please type chmod +x gradlew in the directory where you have cloned the repository and execute the command from there.