I would just early out the ClosetSpotlightItems function if seller is undefined. Seller is undefined in your case at some point in time.

I've also set your default export at the bottom to a named export. This prevents a lot of problems in the future for your codebase: https://basarat.gitbook.io/typescript/main-1/defaultisbad

import React from 'react'
import ClosetSpotlightWrapper from '../layouts/ItemRows/ClosetSpotlightWrapper'
import ClosetSpotlightItemCard from '../Cards/Item/ClosetSpotlightItemCard'

export const ClosetSpotlightItems = ({seller}) => {
    if (seller === undefined) return null
    
    return (
        <>
            <ClosetSpotlightWrapper seller={seller} key={seller._id}>
                {seller.products.map((item) => (
                    <div key={item}>
                        <ClosetSpotlightItemCard item={item}/>
                    </div>
                ))}
            </ClosetSpotlightWrapper>
        </>
    )
}

Do this like, Encode your Object in if Condition and check whether it have data or not

import React from 'react'
import ClosetSpotlightWrapper from '../layouts/ItemRows/ClosetSpotlightWrapper'
import ClosetSpotlightItemCard from '../Cards/Item/ClosetSpotlightItemCard'
const ClosetSpotlightItems = ({seller}) => {
return (
    <>
       <ClosetSpotlightWrapper seller={seller} key={seller._id}>
            { (seller.products) && seller.products.map((item) => (
                <div key={item}>
                    <ClosetSpotlightItemCard item={item}/>
                </div>
            ))}
        </ClosetSpotlightWrapper>
    </>
)
}
export default ClosetSpotlightItems

You can use a ? to skipp the undefined values

{
seller?.products?.map((item) => (
                <div key={item}>
                    <ClosetSpotlightItemCard item={item}/>
                </div>
            ))}