[Home](./index.md) > [kibana-plugin-plugins-expressions-server](./kibana-plugin-plugins-expressions-server.md) > [ExpressionFunctionParameter](./kibana-plugin-plugins-expressions-server.expressionfunctionparameter.md) > [required](./kibana-plugin-plugins-expressions-server.expressionfunctionparameter.required.md) ## ExpressionFunctionParameter.required property Signature: ```typescript required: boolean; ```