CODE releases data under a [Creative Commons Attribution License][1]. That means that anyone is free to use the data for any purpose, as long as the person using the data acknowledges the data source.
There is no required wording for acknowledging CODE data – you are free to use whatever citation format you like as long as you do not suggest that the operators of CODE endorse you or your use of the data.
CODE has the DOI `10.17605/osf.io/zyaqn` which can be used to cite the database in many reference managers.
You can get more advice on your obligations under this license in the [relevant section of the license][2].
[1]: https://creativecommons.org/licenses/by/4.0/
[2]: https://creativecommons.org/licenses/by/4.0/legalcode#s3a