So, where is your actual access token? => https://docs.shopware.com/en/shopware-platform-dev-en/api/admin-authentication?category=shopware-platform-dev-en/api#access-token
And as you can see: your token is of course not valid. Did you passed the maybe the refresh token instead of the access token?
Maybe this helps => https://github.com/laravel/passport/issues/60
Yes @Shopwareianer, you are right. i was passing the wrong token. now i am able to fetch the product list, thank you so much for your valuable response.