So I have been working with WP REST API to fetch custom post type via slug something like below
WORKS

https://www.example.com/wp-json/wp/v2/custom_post_type?slug=post-slug

Now I want to fetch all the custom type posts under custom taxonomy via slug. I am already able to fetch posts via taxonomy id something like below

WORKS

https://www.example.com/wp-json/wp/v2/custom_post_type?custom_taxonomy=123

How can I get all custom posts under custom taxonomy via taxonomy slug like below ???

Does not WORKS

https://www.example.com/wp-json/wp/v2/custom_post_type?custom_taxonomy=taxonomy-slug