Wordpress REST API - get custom taxonomy category posts
I want to use Wordpress REST API to get the posts that are inside a custom taxonomy created by the theme.
The taxonomy is called my_portfolio but if I use this I have this response:
{code:rest_no_route,message:Nessun percorso fornisce una corrispondenza tra l'URL ed il metodo richiesto.,data:{status:404}}
Instead if I use my_portfolio_category I have 4 categories that are called: photo, video, design, web.
I want to retrieve the posts inside the category photos but the only thing I managed to get is the category info.
The API I used is the one down below where 921 is the ID of the category photo, using the slug doesn't work.
https://www.mywebsite.com/wp-json/wp/v2/my_portfolio_category/921
Is there a way to get the posts?