Verifies the specified user attributes in the user pool.
cognitoidentityprovider_verify_user_attribute(AccessToken,
AttributeName, Code)
[required] Represents the access token of the request to verify user attributes.
[required] The attribute name in the request to verify user attributes.
[required] The verification code in the request to verify user attributes.
svc$verify_user_attribute( AccessToken = "string", AttributeName = "string", Code = "string" )