Problem filtering post by taxonomy and term_id_str

or can you tell me how to filter posts by taxonomy, cat and category name

I have tried to use it as 1/posts/cat:23

or https://example.com/wp_api/v1/posts/taxonomy:ad_cat?terms_id_str:43

I am failing to get a response. It says Nothing Found. Help

You could use any combination of cat, category_name, tag, and taxonomy.

Please refer to the documentation for a more in depth explanation of how to use those parameters.
https://github.com/voceconnect/thermal-api/blob/master/README.md#parameters