fix some bug

src/types/Customer.ts

@@ -8,7 +8,7 @@ export type BodyAreaValue = {
 };
 
 export type Customer = {
-	code?: string;
+	code?: string | null;
 	name?: string;
 	gender?: CustomerGender;
 	age?: number;
@@ -19,7 +19,7 @@ export type Customer = {
 	remark?: string;
 	disease?: string;
 	conditioningPart?: BodyAreaValue;
-	introducerCustomerId?: string;
+	introducerCustomerId?: string | null;
 	creatorUserId?: string;
 	lastSignInAt?: number;
 	introducerCustomer?: Customer;