meta_data on order creation (Rest API)

I am working with the rest api (v3) and ionic. I am trying to create an order (which works fine) but along with that order I am trying to add meta_data. I can see the meta_data in rest with orders that have been submitted though wordpress. When I submit the order I am getting the following error:

data: {status: 400, params: {meta_data: “meta_data is not of type array.”}}
message: “Invalid parameter(s): meta_data”

Here is a code snippet:

data = {
payment_details : {
method_id: paymentData.method_id,
method_title: paymentData.method_title,
paid: true
},
billing: this.newOrder.billing,
shipping: this.newOrder.shipping,
line_items: orderItems,
meta_data: {
“vets_name”: this.newOrder.meta_data.vets_name,
“vets_city”: this.newOrder.meta_data.vets_city,
“vets_state”: this.newOrder.meta_data.vets_state,
“vets_phone”: this.newOrder.meta_data.vets_phone,
}

Without the meta_data, the order is created without a problem.

Thanks!