How do you enter reasons when annotating an assessment using RecaptchaEnterpriseServiceClient?

When I try to include reasons when annotating an assessment I always get this error:
```
Error: 3 INVALID_ARGUMENT: Invalid reason.
```

For example I might use the following:

```
const response = client.annotateAssessment({
name:projects/111111111111/assessments/11111111111111111,
annotation: "LEGITIMATE",
reasons:["REASON_UNSPECIFIED"]
});
```

My node version is 16.19.0
My npm version is 8.13.2

Please see my post on Stack Overflow for more details:

https://stackoverflow.com/questions/76369090/how-do-you-enter-reasons-when-annotating-an-assessment-using-recaptchaenterprise

Thank you.