public static boolean fieldRequired(Field field, @Nullable io.swagger.v3.oas.annotations.media.Schema schema,
			@Nullable Parameter parameter) {
		Boolean swaggerRequired = swaggerRequired(schema, parameter);
		if (swaggerRequired != null) {
			return swaggerRequired;
		}
		boolean annotatedNotNull = annotatedNotNull(Arrays.asList(field.getDeclaredAnnotations()));
		if (annotatedNotNull) {
			return true;
		}
		return !fieldNullable(field);
	}
Is field required.

@param field     the field
@param schema    the schema
@param parameter the parameter
@return the boolean
@see Parameter#required()
@see io.swagger.v3.oas.annotations.media.Schema#required()
@see io.swagger.v3.oas.annotations.media.Schema#requiredMode()
springdoc-openapi-starter-common/src/main/java/org/springdoc/core/utils/SchemaUtils.java