Shopify REST API: Unable to add a new product variant with new option type getting error "Option values provided for 1 unknown option(s)" - rest

Question

when creating a product in Shopify via the REST API, adds a default option and variant like below
"options": [
{
"id": 9651869188247,
"product_id": 7644173172887,
"name": "Title",
"position": 1,
"values": [
"Default Title"
]
}
]
Variants:
{
"variants": [
{
"id": 42211487744151,
"product_id": 7644173172887,
"title": "Default Title",
"price": "1.00",
"sku": "",
"position": 1,
"inventory_policy": "deny",
"compare_at_price": null,
"fulfillment_service": "manual",
"inventory_management": "shopify",
"option1": "Default Title",
"option2": null,
"option3": null,
"created_at": "2022-06-17T17:18:24+05:30",
"updated_at": "2022-06-17T17:18:24+05:30",
"taxable": true,
"barcode": null,
"grams": 0,
"image_id": null,
"weight": 0.0,
"weight_unit": "kg",
"inventory_item_id": 44310083534999,
"inventory_quantity": 0,
"old_inventory_quantity": 0,
"requires_shipping": true,
"admin_graphql_api_id": "gid://shopify/ProductVariant/42211487744151"
}
]
}
I want to update the existing Option and Variants of a product to show "Color" & "Size" as options and variants of them. For that I tried the Shopify Rest API but that still is raising the below error
request model:
{
"variant": {
"product_id": 7644173172887,
"option1": "red",
"option2": "small",
"price": "1.0",
"title": "S"
}
}
response :
{
"errors": {
"base": [
"Option values provided for 1 unknown option(s)"
]
}
}

Answer 1

You are not specifing what endpoint you're using but I can see that you're specifing the Product Id and that should not be the case. If you need to add a new variant this is the request you should do
POST https://yourstore.myshopify.com/admin/api/2022-04/products/7644173172887/variants.json
{"variant":{"option1":"Red", "option2" :"Small", "title": "Red", "price":"1.00"}}
You will also need to update the current "Default Title" variant (I suggest, if possible to create the product with a valid variant).
PUT https://yourstore.myshopify.com/admin/api/2022-04/variants/42211487744151.json
{"variant":{"id":42211487744151,"option1":"Red","option2" : "S", "price":"99.00", "title" : "Red"}}